Hearthstone - match-making and bottom-feeding

Most players play every day to win their daily quest. Most daily quests involve winning in PvP matches. Thus, many players end up bottom-feeding: they keep their PvP ranking low so as to win more easily and complete their daily quest faster. That's why 90% of Hearthstone players are below rank 10 in ranked mode.

To reach the number of wins for their daily quest faster, players may want to concede and start another game when they see they have no chance in the current one. There are several techniques to gauge an opponent and the likelihood to lose:

• A golden hero protrait indicates the player has won 500 games with that hero. It is a veteran player, most likely with lots of good cards.
• Decks composed of 4+ legendary cards, especially Sylvanas, Dr. Boom, or Alexstrasza, are from players who spent a lot of money.
• Purchased heroes means the player has certainly spent a lot of money on card packs as well.
• A legendary card back indicates the player was dedicated enough to reach the top .25% of the player base.
• Old card backs indicate the player is a veteran, and must have good cards.
• Heroic dungeon card backs are awarded for clearing a dungeon in heroic mode, which requires many good cards.

Having players with different skill levels playing together is problematic. Veteran players tend to have better cards and more skill than beginners. As a result, beginners may frequently go on long loss streaks. Loss streaks are very unpleasant, and come to mind faster than win streaks. So when players talk to their friends about Hearthstone, they are more likely to complain than to brag. That won't encourage their friends to start playing.

There are solutions to bottom-feeding. One solution is to pool beginners together so they don't get beaten up too quickly. Another solution currently in place in Casual Play, Tavern Brawl, and legendary-rank games, is using a ranking hidden from players such as MMR. Hiding player's rank from them prevents them from knowing where they stand, and the average skill and cards to be expected from their opponents. But players can easily cheat the system and drop their MMR by conceding games before they even started.

A great solution would be to consider both the player's ranking (as is currently the case) and the rarity of the cards in their deck. In fact, websites listing Hearthstone decks already take into account the rarity of the cards in a deck by providing a dust cost. Epic and legendary cards cost a lot of dust, and are either useless (and therefore unused), overpowered (and therefore always used), or the keys to unlocking synergies in a deck (which is where the game is interesting). I think it would make sense to at least take them into account when matching players together.

Habits

Notes from a French magazine called Ca m'interesse from January 2014. One article talked about choices, habits, and routines. Some findings are applicable to game design.

Richard Weiseman, a psychologist, followed 3000 people taking New Year resolutions. Half say they will hold their resolution on day 1. 12% manage it after one year. Weiseman gives tips on how to keep your resolutions, such as telling others about your resolution (to put peer pressure on yourself), avoiding previous (failed) resolutions (to prevent frustration), breaking it in smaller achievable steps (to prevent hopelessness), and giving yourself rewards for achieving these steps (positive reinforcement). It's been covered elsewhere too.

Based on previous research, Philippa Lally, another psychologist, suggests that it takes around two months working effortfully on new behavior to turn it into a habit.

Future hypothetical rewards (e.g. slim body in a month) are higher to accept than instant gratification (e.g. eat tasty food right now) because they require an effort of imagination. Solution: make future rewards more visible.

Baba Shiv, professor of marketing, asked 165 undergrads to pick either a chocolate cake or a fruit salad. The chocolate cake has a positive affect and negative cognition, ie it's emotionally appealing but you know you should not take it. The fruit salad is the opposite: negative affect and positive cognition, ie it's the rational healthy choice. In both groups, participants were asked to remember a number throughout the experiment. One group was given a 2-digit number (low cognitive load, ie high processing resources) and the other a 7-digit number (high cognitive load, ie low processing resources). 41% of the 2-digit group picked the tasty cake vs 63% in the 7-digit group. Under heavy cognitive load, people are more likely to choose options that are immediately pleasing. As a side note, when the presentation of the choice was through photos rather than the actual items, the difference between the two groups disappeared.

If I perceive a task as more difficult, I will expect a higher reward. It is not just about being strong-minded, but also about my perception of the task's difficulty.

Diablo 3 - the item game

In item games, the main goal of players is to continuously upgrade their gear. Diablo 3 (D3) is the perfect example: kill monsters in order to drop better gear in order to kill monsters faster. Bungie just released Destiny, an item-game FPS budgeted with half a billion dollars. Yet Destiny could learn from Diablo 3. So here are some thoughts about the item game in D3.

Prevent farming ...

In D3, like in D2, the drops are completely random: with a few exceptions, nearly any item can drop from any monster or wreckable object (e.g. jars). The odds are just higher for harder monsters, and way lower for wreckable objects. The exact drop rates are secret (except the 10% legendary drop rate from Kadala). This secrecy has led to various rumors and tinfoil hat theories about how loot can be influenced.

D3 has, or used to have, farming spots such as the Decaying Crypt, but they were mostly for XP, not for drops. In D3, farming boss monsters actually brings fewer drops than farming normal or elite monsters. This contrasts with Diablo 2, where players were grinding bosses like Baal or Diablo for XP and loot. So in a way, the grind in D3 is less boring than in D2.

... Yet allow farming

As of October 2014, there are 2 exceptions to what I just wrote: 1) bounty rewards like RoRG or Helltrapper, and 2) Hellfire Amulet.

The RoRG was introduced in February 2014. It is a mandatory item to reach the game's highest difficulty levels. Players have to camp Act-1 bounties to get one with good rolls. To farm as quickly as possible, players join co-op games to split farm: instead of spending 15-20 minutes completing the 5 bounties together, they each complete a bounty in 5 minutes. I am surprised that the developers did not see it coming: split farming is very clearly not how we want players to play the game. Yet nearly a year later, they still have not changed the bounty system.

The Hellfire Amulet is not as mandatory compared to the RoRG. But its bonus is so useful that all of the top players have it. Farming it is somewhat more fun than farming for RoRG, since it is a quest in itself: a) hunt for the 4 Keywardens on the game's largest maps to obtain 4 keys, b) combine the 4 different keys into a portal, c) kill 2 super bosses at once, a somewhat more difficult task than the Keywarden hunt, and d) combine 4 super bosses' loots to obtain a Hellfire Amulet.

The Reaper of Souls expansion

From launch in May 2012 until the retirement of the Auction House (AH) in February 2014, players were mostly buying their gear from the AH, and sometimes grind-crafting it. They nearly never dropped it themselves. Legendary weapons had 7-8 affixes. After the AH retired, Loot 2.0 arrived, and the expansion Reaper of Souls (RoS) shortly after that. Legendary weapons now have 4 primary and 2 secondary affixes. Secondary affixes do not matter much (e.g. more XP when killing a monster), so RoS drastically reduced the item entropy.

The expansion also reminded me of Blizzard's somewhat elegant solution to a common MMO problem. Most MMOs in the early 2000s had the same problem: players who have been playing for a year have too much of a head start compared to players who have been playing for 3 months. New players are hopeless, especially in PvP situations. World of Warcraft solved this problem with what I call expansion gating: WoW vanilla capped the character level at 60 and item level at 92. Until the first expansion came out to increase these two caps, players were gated there. The advantage of expansion gating is that it gives the same chance to old and new players. The main drawback (if any) is mudflation. Diablo 3 is no different: level-70 items have twice more DPS than level-60 items. Thus when the expansion launched, players threw away all the gear they had acquired before.

Few links to other end-game activities

Item games have a great loop, but it is not enough in itself. D3 launched in May 2012. The Auction House (AH) launched in May 2012 too, so players could play two games in one: the action RPG and the auction game. Note that you did not need to play the aRPG to play the auction game, but you did need to buy gear off the AH to play the aRPG well. Had it been the opposite, I think the game would have been much better.

In July 2012, the developers realized that the item hunt is just not enough for a long-term sustainable end-game. Since launch, the game also allowed players to hunt for achievements and start new characters (in softcore or hardcore). In August 2012, the developers added the leveling up grind through 100 Paragon levels. Every Paragon level increased the chance to drop an item and the amount of gold dropped by 3%. In February 2014, Paragon levels became infinite, and the 3% bonus was removed. Clans and communities were also added in February 2014. Since August 2014, players can compete on the greater rift leaderboards, and start new seasonal characters (in softcore or hardcore). Interestingly, the item game is completely independent of all other end-game activities (except the AH and the original 100 Paragon levels increasing magic find and gold find). In other words, the item game of Reaper of Souls could be directly copied into another game without having to also copy the other activities.

Assist bundles in Forza 4 and 5

Forza Motorsport 4 is a realistic simulation racing game. If they want to, players can handle the clutch, tire-wear, and other minute racing details. For beginners, the game provides assists that take care of these details automatically. For example, the Braking and Steering assists make turning easier, the Line assist shows the optimal path to follow, and the Transmission assist takes care of switching the gears. For a description of the assists, check these websites.

While I was at Microsoft Research during the Summer of 2013, my mentors and I looked at patterns of progression in FM4. Among the things we published, we found that players rarely used the assist bundles shipped in FM4. FM5 came out in November 2013. This post describes how the FM5 designers used our findings on FM4 to improve the assist bundles.

Assists in FM4 and FM5

Here are the assist bundles shipped in FM4.

	Easy	Medium	Hard	Advanced	Expert
Steering	Assisted	Normal		Simulation
Stability	ON		OFF
Traction	ON			OFF
Brakes	Assisted + ABS		ABS only	OFF
Transmission	Automatic			Manual	Manual + clutch
Trajectory Line	Full		Braking only		OFF
Damage	Cosmetic	Limited		Simulation

Below are the FM4 bundles we suggested, based on player data in Career mode.

	Easy	Medium	Hard	Advanced	Expert	Comments
Steering	Assisted	Normal		Simulation		Unchanged
Stability	ON		OFF			Unchanged
Traction	ON			OFF		Unchanged
Brakes	Assisted + ABS	ABS only		OFF		ABS-only from Medium onwards
Transmission	Automatic		Manual		Manual + clutch	Manual from Hard onwards
Trajectory Line	Full	Braking only		OFF		Bumped down: shifted all cells to the left.
Damage	Cosmetic	Limited	Simulation			Simulation from Hard onwards

And below are the bundles shipped in FM5.

	Easy	Medium	Hard	Pro	Veteran	Comments
Steering	Assisted	Normal				Simpler: now binary. In Custom bundle, Assisted steering forces Assisted brakes.
Stability	ON			OFF		Bumped up
Traction	ON				OFF	Bumped up
Brakes	Assisted + ABS		ABS only			OFF available in Custom bundle.
Transmission	Automatic				Manual	Bumped up. Clutch available in Custom bundle.
Trajectory Line	Full		Braking only			OFF available in Custom bundle.
Damage	Cosmetic			Simulation		Simpler: now binary.

In short, the bundles in FM5 are easier than their FM4 equivalent because the Stability, Traction, and Transmission assists have been bumped up. Clutch transmission, ABS-OFF, and no trajectory line are only available in a Custom bundle. The FM5 designers did not exactly follow the bundles we suggested. Why is that? See below.

Assist progression

For each race number, we look at how much of the player base still has an assist enabled. The goal is to see how fast players disable an assist. The graph below shows exactly this.

Let's take the Transmission assist as an example. In the first race, the Transmission is automatic for 80% of players (the orange line starts at 0.8), manual without clutch for 15% (the space between the orange and brown lines), and manual with clutch for 5% (the brown line starts at 0.95). Even among the players who reach 100 races (17% of the total player base, cf gray line), only 15% use a manual transmission with clutch. That's why in FM5, manual transmission with clutch is only available in a Custom bundle: very few players use it. Same story for the Trajectory Line-OFF and ABS-OFF assists. In the end, the FM5 designers actually used our findings in their product!

Of course, we need another study to assess whether FM5 players are actually using the default FM5 bundles or not.

A note on Rewind

When you miss a turn, you can press Y to rewind the game and try the turn again. In FM4, the ability to rewind is an assist. Turning the assist OFF grants a 20% credit bonus at the end of a race. In FM5, each rewind costs 1% of the race's credit. I like this change for several reasons:

• In FM4, I enabled rewind in case I needed it during a race. But I only rewinded every 3-4 races. 20% was a lot of credits missed, though, so it felt a bit frustrating.
• A fixed price encourages players to rewind as much as they want. So, to get more bang for the buck, they increase the difficulty of the AI opponents, and rewind every time they don't make a perfect turn. This is the same lame trick as saving-and-rerolling in RPGs. Racing this way is excruciating. It also takes longer to complete a race, so the amount of credits gained per hour may actually be lower with more difficult AI.
• FM5's rewind cost is proportional. This is advantageous for players who rewind rarely, and disadvantageous for those who rewind dozens of times per race.
• I prefer paying the cost automatically, in the stats screen at the end of a race, rather than manually, through an assist menu before the race.

Rewards, pacing, and dopamine

Rewards and pacing

There is something mysterious when people read through 1000 pages of Cryptonomicon, a 1999 novel from Stephenson, or through the thousands of pages of Martin's A song of ice and fire. What keeps people reading? Here are some rewards that both authors use throughout their books:

Reward	Pacing	Description
Character progression	Randomly (but fits the story)	The protagonist learns new skills, grows up, meets love, learns a lesson of life, or gets rich. We care about this character's well-being because we empathize.
Action and passion	Every 3-10 pages	When stuck in difficult situations, the reader knows that the hero can not die, so she asks herself: how is the hero going to get out of this alive? (Except sometimes, main characters actually die, leaving us in shock). The same applies for romantic scenes, where we wonder not if, but how it's going to work out between two characters.
Story progression	Every 10-30 pages	Right from the start, the authors put under the reader's nose a bunch of questions: what is happening, why is this guy so mysterious, and so on. The reader wants to know the answers, so she keeps reading until answers are provided, along with new mysteries to figure out.

Looking at blockbuster action movies such as The Bourne Ultimatum, the same kind of pacing emerges: action scenes are followed by the protagonist learning about his past. Then the plot moves on, the character meets new people, finds himself new tasks to do, and back to action scenes.

These rewards and pacing also echo those found in games and mentioned in a class on game balance from Ian Schreiber: gains in character power, discovery of new areas, and progression of the story are rewards to be used at irregular intervals to keep the player engaged. So reading books, watching movies, and playing games seem to provide similar rewards.

Dopamine

Let's dig down to the physiological level of rewards. Most of the articles dealing with the physiological response of gaming revolve around addiction. For instance, a 2012 NY Times article reports that Zynga helps addict millions of people to dopamine, a neurochemical that has been shown to be released by pleasurable activities, including video game playing, but also is understood to play a major role in the cycle of addiction.. To that, the Zynga co-founder replies: Given that we're human, we already want dopamine. And that does not calm things down. So let's look at a less controversial topic: the physiological response of reading. This is not a survey of the field, but rather some picks from a few Google searches - nothing very serious.

First, according to Farland, a current writer, the dramatic structure of stories (exposition - action - climax - denouement) matches the bio-feedback of hormones such as dopamine, adrenaline, and cortisol. He says: As a person "hunts" for clues, or for a way out of a problem, the brain rewards the person by releasing dopamine as a reward. [...] When you reach the climax of the novel, [...] you reach the climax of your emotional exercise. When the story ends [...] your stress is released. The adrenaline and cortisol stop flowing.

As notes from a psychology class on stress can tell us, cortisol is the key hormone of stress. Adrenaline is the hormone that tells our body to be alert. And finally, dopamine is in charge of rewarding our brain.

So what happens when we start reading? Some have guessed that we are having pleasure because reading is a tough task, and our brain rewards us for completing such a hard task. This seems confirmed by a 2001 study who showed that transitioning from rest to reading produces the same increase in dopamine concentration as transitioning from rest to memory-intensive tasks (something cognitively demanding). Although, a 2000 study seems to reject this hypothesis. Something that might be worth investing is whether reading a microwave-oven manual generates as much dopamine as reading an exciting short story where the action starts right from the start.

It may actually be more complicated: the dopamine concentration could actually not indicate our pleasure, but our expectation of pleasure: dopamine motivates us, increasing our energy and drive and compelling us to engage in the pleasurable activity. If everything is as nice as the brain predicted, dopamine levels remain elevated. If things turn out even better than the brain hoped, dopamine levels are increased; we engage in the pleasurable activity even more vigorously. If, on the other hand, the activity is less pleasurable than we thought it would be, dopamine levels plummet.

Back to games

So, what can we conclude about games? First, much like movies and books, reward us by generating dopamine when we succeed at a difficult cognitive tasks such as a head-shot in an FPS, or a successful Chess trap. That is pretty close to fiero, and in fact, Bateman already suggested in 2008 that fiero is a cocktail of epinephrine and dopamine. So, nothing brand new here.

Perhaps more interesting, long-term enjoyment seems to require the dopamine to yo-yo - which is bad. Let us assume that our brain produces dopamine by expecting a nice event. Then when our brain is done with those nice events, the dopamine level will decrease. That would be a horrible yo-yo if there were only one kind of event, but books, movies, and games, have at least three: action, story, and character events. So alternating events and interweaving them in such a way that our brain is always on the lookout may keep dopamine, and pleasure, at high levels instead of making it yo-yo.

There might be a few gotchas, though. First, the magnitude and the lifespan of the dopamine burst depends on a lot factors. Grinding monsters for a drop is only pleasurable so long as the brain is expecting that item to drop. After a couple days, the dopamine is all gone, and it's just boring. Some studies should investigate the average magnitude of an "achievement unlocked!", or the lifespan of a boss kill or a level up.

Second, dopamine bursts may not stack. The brain may be too busy expecting a story progression event that it may ignore, or even worse, be displeased, by a character progression event: it was not expecting it! This limitation does not seem cognitive, but rather emotional, so maybe people with higher EI could stack expectations and dopamine bursts more easily than indifferent people who say "it's just a game"?

Third, and to finish as we started, with books: Stephenson and Martin alternate their character viewpoints chapter after chapter, possibly to keep the reader's attention. By the way, they rarely handle more than 7 characters at the same time, since 7 is a magic cognitive number. These changes in views often cut short the action, so the reader may get frustrated, or even vexed for being tricked to continue reading by the exact same three mechanisms every chapter. It is interesting to know why people keep reading those long books, but that last reason is exactly why I stopped.

Stress: appraisal, coping, and physiology

Notes from the first few weeks of a class on stress by Sally Dickerson taught throughout Spring 2012.

Basics

Eustress = positive/healthy stress. Example: wedding, vacation. As opposed to distress. Three phases of stress: stressor, appraisal, and response.

The stressor is the eliciting event; examples are being stuck in traffic, having an exam, or arguing with your partner. Stressors break homeostasis, our stability with the environment. A stressor can be acute or chronic. Durations of exposure to stressor vs duration of perceived threat vs duration of stress response.

The response happens at all levels: emotional (e.g. fear), physiological (e.g. BP increases), and behavioral (e.g. running away). The response aims at bringing back homeostasis. If it lasts for too long, sickness appears because of the general adaptation syndrome.

Appraisal

Evaluation/interpretation of the harm, threat, and overwhelmingness of the stressor to determine the response. Individual- and context-specific. Individuals who are told beforehand that "pain is going to happen" have stronger physiological response to a stressor than individuals told "it's just a formality, nothing too big". Appraisal consists of the primary appraisal and coping.

Primary appraisal

The individual estimates the importance/meaning of the stressor, and its implications on her well-being. "This is the most important day of my life" vs "No big deal". Three types of primary appraisals:

Type	Description	Emotions generated	Physiological response	Example with stressor = "just got fired"
Harm/loss	The damage has already been done	sadness, anger	damaging	"Everyone looked at me packing my stuff"
Threat	Possibility of future damage	anxiety, fear	damaging	"How am I going to pay the rent?"
Challenge	Potential to overcome and profit.	excitement	positive/healthy, smaller than harm or threat	"Let's find a better job"

Primary appraisal moderators:

• sense of control. If the individual feels (no need to actually be) in control = less stress. But inappropriate sense of control increases stress: individuals blame themselves for an event they actually could not influence, especially if the event is big: "it's my fault if my car's brakes broke and it caused an accident".
• predictability. Know when stressor happens (and/or does not happen) reduces stress. Unless stressor very frequent or very rare, or horrible outcome (e.g. earthquake).
• ambiguity. If information on the stressor is vague, stress increases.
• centrality. If the outcome is important to the individual, stress increases.

-	Optimists	Pessimists
Face problems	actively	passively
Receive positive events	wrt themselves, in general and absolute terms	wrt other people, in specific and relative terms
Receive negative events	wrt other people, in specific and relative terms	wrt themselves, in general and absolute terms
Example: just got fired	"my skills were not a good match for that company" (external)	"i am a failure" (internal), "I can't do anything" (global), "I'll never get another job" (absolute)

Coping

The individual estimates how well she can cope with the stressor. If she estimates she does not have enough resources to cope with the stressor, the stress response will be bigger. Coping can happen before, during, or after a stressor, and it varies in time. When it happens before, it is called proactive coping (e.g. keep water bottle packs and a torch light at hand in case of a disaster). Even when given information, if people feel like they can not change the outcome, or if they underestimate the problem, they may not pro-actively cope.

Avoidance or minimization are effective coping strategies for short-term stressors. Vigilance and confrontation consist of gathering information or take direct action, and are more effective in the long-run, but fail if the information is of poor quality (e.g. individual googles "soar throat" symptoms and finds herself on a page about a deadly disease). Social support from others is a form of coping; the individual reduces her stress response by receiving moral support, information about the stressor, or tangible resources (money, workforce, ...) to overcome the stressor.

Coping can be problem-focused, emotion-focused, or both. Problem-focused coping is constructive (e.g. studying for an exam), and effective when the individual can have an impact on the stressor. Emotion-focused coping does not address the problem, but rather regulates the individual's emotions cognitively (how people think about the stressor, e.g. "it could be worse"), or behaviorally (doing something, e.g. jogging or eating chocolate to feel better). Emotion-focused coping is effective when the individual does not have control on the stressor.

In general, optimists deny less and cope better than pessimists. For instance, Type A individuals are competitive, easily provoked, fast-paced, and impatient. They have more risky behaviors, are less likely to receive social support, and have bigger physiological responses. Hence, they are more sensitive to stress. Moreover, according to a 2006 study (see also the pdf), Big 5's Neuroticism is related to distress and emotion-focused coping, while Conscientiousness is related to task-focused coping.

Methods for assessing stress

• After an unpredictable/random trauma (e.g. a disaster): from groups or individuals. Problem: getting a baseline before the stressor happened. Solution: compare with similar groups or individuals who were not exposed to the trauma.
• Life events: go through individual's recent events to assess her current stress level. Depending on the category of the individual, each event has a standard weight (e.g. for undergrad students, "death of relative" = 100 points, "got a ticket" = 20 points).
• Daily stressors: going over recent events or maintaining daily diary (prompted by researchers every day at the same hour).
• Lab experiments: standardized stressor, influence on appraisal (but appraisal ultimately depends on the individual), can measure physiological response, but not generalizable.

Physiologically

Cortisol is a hormone released by the adrenal gland in response to stress. Its function is to have the body generate energy by breaking body fat into glucose. In the circadian rhythm, it naturally peaks at wake up, and falls at sleep time.

Cognitive tasks such as mental arithmetic increase the concentration of cortisol in the blood. Public speaking increases it even more. The two combined generate more than the sum of each. Public speaking exposes our differences with other people, and invites criticism: it is a social evaluative threat. This threat is increased if we are captured on permanent record, in front of a critical audience, or compared to others negatively. On the other hand, emotion induction (such as watching a scary movie) or exposure to noise do not influence the cortisol level.

Uncontrollability increases the cortisol level. Hence, false feedback to a stressful task will increase the cortisol level. Changing the task difficulty on the fly, harassing the individual under stress, or adding noise and distractions increases stress. An uncontrollable social-evaluative threat generates the biggest cortisol response, and a slow stress recovery: the cortisol level remains high longer.

Novelty and diversity also seem to increase the cortisol response. Facing many stressors at a time seems to increase the cortisol level logarithmically with the number of stressors. On the other hand, facing a stressor as a group reduces the individuals' cortisol response. Similarly, in a 1991 study, women's stress response was found to be smaller if their pet rather than their friend was with them: as opposed to the friend, the pet provides support without judging.

[Literature] Fundamentals of Game Design, ch 9: Gameplay

What makes a game fun

50% from quality assets, UI, and code. 35% tuning and polishing. 10% imaginative level design. 5% innovation. A pinch of luck.
Guidelines

• Gameplay before story and graphics
• get a feature right or leave it out
• player-centric, know your audience
• abstract or automate the boring parts
• be true to your vision, do not add stuff for marketing or in hope of getting more players
• aesthetics matter

Challenges

Gameplay is in the challenges.

Challenge hierarchy: to complete the game, the player has to complete chapters, levels, missions, and atomic challenges. Atomic challenges are what player focuses on at the moment. The game victory condition should be explicit, as well as the atomic challenges. Intermediary challenges can and should be implicit: the fun comes from figuring out how to use the atomic tools to reach the end goal. That's why the player should be rewarded whatever path she took or means she used.

Many simultaneous atomic challenges put stress on the player (e.g. Impossible Super Mario levels). Difficulty = intrinsic skill + stress. Intrinsic skill = level of skill required to overcome a challenge without any time limit. Sudoku is pure skill. Stress = perception of time pressure for a given skill level. Tetris is pure stress. Therefore, to make the game easier, give more time to complete skill-based challenges.

Commonly used atomic challenges:

• Physical coordination (hand-eye): speed, accuracy, timing and rhythm.
• Logic and maths: challenges solved by reasoning power alone. Rubik's cube, puzzles
• Race: time pressure reduces strategic thinking.
• Factual knowledge: Trivial Pursuit, quizzes
• Memory: French Tarot
• Pattern recognition
• Exploration: spatial awareness, locked doors, traps, mazes, teleporters. Should still have challenges, otherwise it's sightseeing.
• Conflict: strategy, tactics, logistics, defend weak units, stealth. Checkers, chess, Heroes of Might and Magic.
• Economic: accumulate resources (RTS), balance a complex economy (SimCity), care for living things (Black and White)
• Lateral thinking: there is no obvious solution.

Actions

Actions are IG events directly and immediately influenced by player's input. Player spends most of her time using actions to overcome atomic challenges. Therefore, particular attention should be given to how actions can overcome basic challenges.

Some actions do not overcome challenges, but provide hooks for unstructured play (honking in a racing game), creation/expression (customizing your avatar), socialization (emotes), and story participation. There are also meta-actions: loading, saving, configurations, exit, ...

Saving

Save files are good for testing and debugging. In general, saving harms immersion and story flow/discovery (player can see different branches by reloading and taking different choices). Always allow the player to save and reload the game. Saving can be implemented through:

• level passwords (levels of Lucky Luke for Gameboy),
• save slots (player can keep copies of his progression and try different things, Doom),
• quick save when pushing a key (Baldur's Gate 2),
• automatic save/checkpoints (mid-level checkpoints in Mario platformer series).

[Literature] Game Balance ch7 - Advancement, progression and pacing

My notes from course 7 of the Game Balance class of Summer 2010, by Ian Schreiber.

Progression is ...	in games that are ...
absolute	PvE/single player
relative to other players	PvP/multiplayer

Flow has two problems: different player audiences have different skills, and players learn throughout the game.
Balance = overall game difficulty, does not solve these problems. Balance only matches audience expectation.
Progression/Pacing = keeping the player in the flow zone. As player skill increases, so do challenges. Progression ensures the game ends in the time frame said by the box (1min for arcade, 40h for RPG, etc.). If the game is endless, then progression = end-game rewarding structure(s).

When transitioning from mid- to end- or elder game, the objectives change from progressing to something else. Game designer has to find something for the player to do. Ex: WoW guild raiding or making your house cute in Farmville/Sims. Problems: some players may like the progression game but not the elder game. The power gathered during progression game should be available and enjoyable during elder game.
Tips:

• As playtesters test the game, they become experts => the game gets tuned harder => make the game easier at the end, and/or keep some playtesters for the end.
• Let players adjust the difficulty themselves (more challenging but also more rewarding levels or adjusting the difficulty level at any time). In PVP, difficulty adjustment should be voluntary (handicap, resources at the beginning, ...).

PVE

Perceived difficulty = (game power challenge + game skill challenge) - (player power + player skill), with:

• Game power challenge = stats (doubling opponents HP makes the game harder)
• Game skill challenge = new enemies or better AI, direct challenge to the player's skill (you need to play better) and not a player's power (you need more hit points to win). A game designer can control power-related, but not skill-related components of difficulty.

Large luck component or shallow mechanics: a short increase in player skill as the player masters what little they can at the beginning. Then skill plateau (player is as good as she can ever be). A minute to learn, a minute to master. This is the design of educational games (where skill is not the priority).

Giving practice zones where new weapons or powers are acquired makes players learn/increase their skill faster. Skill gating = progressively harder challenges, guarantee that if players complete a challenge, then they are ready for the next. Skill gating != practice zones.

Psychology: “reward schedule” or “risk/reward cycle”: you don’t just want the players to progress, you want them to feel like they are being rewarded for playing well. Reward not too rarely and not too often. Many small rewards are more efficient than a single big reward. Regular rewards = bad. Reward for something players were looking for (otherwise the game seems too easy) and not for a random event (eg "inflict exactly 123 dmg"). 3 kinds of rewards related to progression: increasing player power, level transitions, and story progression.

Increasing player power

If the most fun toy in your game is only discovered 2/3rds of the way through, that’s a lot of time the player doesn’t get to have fun. How do you actually keep the player engaged when you've given away all the cool toys early in the game? One way is if your mechanics have a lot of depth, you can just present unique combinations of things to the player to keep them challenged and engaged. Warning: this is really hard to do in practice. You can also use other rewards more liberally after you shut off the new toys: more story, more stat increases, more frequent boss fights or level transitions. Also, toy upgrades.
Better shorten the game than have it too long and boring.

Level transitions

Each level takes a little bit longer than the last: fast progression at start engages player into the game, later levels can be longer because player wants to know the end of the plot.

Story progression

Story really IS a reward. There should be a match between story complication/climax curve and the difficulty curve. Ex: tutorial = exposition scene, miniboss = rising action, final boss = final climax. Final boss should not be as demanding on player skill as kill 10 rats.

Pattern: do not reveal the story only during level transition; instead, revealing additional background story immediately after a fight (even an easy one) makes players feel like they earned it. (But do not do that all the time otherwise it becomes predictble!)

PvP

Acquiring more power than opponents = primary reward. PvP has more options to play with than PVE because everything is relative, there's no defined level/stats to reach to be "strong".

negative feedback loops => more power when behind and less power when ahead => best player alternates => depends on opponents, no one is left behind (ex: Mario Kart with dynamic difficulty adjustment).
positive feedback loop => more power brings more power => best stays best => independent of the opponents, game ends faster, bad start is deadly (ex: League of Legends).

	positive sum	negative sum	zero sum
Definition	sum of all player resources increases over time	players lose power over time. Goal = lose power more slowly than opponents.	fixed amount of resources on the table
Example	Catan, Agricola	Chess	Poker
Positive feedback
Negative feedback			Solution: Each player spends time in the lead before one player's final blow ends the game.

When both players have realized who is going to win, the game should end quickly.

[Conf] Game design = learning design = game design

On June 19th, James Gee gave the opening keynote at FDG2010. You can find the abstract page xix. Here are some notes I took during the talk.

Games convey learning better than schools do.

A concentrated sample is a basic language sample for a 1-year-old kid learning language. But people do not speak simply enough, they do not send basic samples only. Nature's solution is: kids filter and simplify what they receive, they can only process simple sentences. Kids are built to be limited. What could be a boss battle in language? For games, the problem is: how to be sure players get only the bits of information they need to progress. Games are guided experience on concentrated sample for future learning. Each level is a preparation for the following level, each level is learning. A boss is here only to test if the player is prepared to learn more. A better player is a better learner.

Experts only know one thing, they overvalue it and undervalue their other knowledge. WoW is distributed experts who also understand other classes' expertise. With the Damage Meter add-on, DPS free-riders are spotted.

Learning is helped by the emotional impact found in games. Why would I save people in the game? Why would I play? The story is here to kick-in emotions and motivate players. Stories are the only way to do it.

There is always performance before competence. The problem is trainees need to trust their trainers, otherwise they fear to perform. In games, there is performance: it is players looking at other players or NPC. Bonus: the intelligence is distributed. The community helps learning. This works particularly well with modding.

A game is fair when players admit I can win if I get better.

For Baby Boomers, intelligence meant speed and efficiency. For today kids, it is adaptation.

[Literature] On virtual economies

On Virtual Economies by Castronova in 2003 points at the growing importance of VW on real-life society. Similarly to real-life, people live, consume and generate profit in VW. However, the software nature of VW means controlling the market is much more efficient for the regulating authorities. In cyberspace, the coding authority does indeed have the power to create and destroy any amount of any good, at virtually zero cost. What are the possible evolutions for these VW economies? How do VW economies influence RL economies?

Establishing an economic model of VW

Economists are forced to recognize that VW are not only mere entertainment, they also have a RL impact on people. Indeed, economists do not make any difference between real and virtual items or properties: if people are willing to incur large time and money costs to live in a virtual world, economists will judge that location to be lucrative real estate, regardless of the fact that it exists only in cyberspace. For economists, our behaviors follow constraints: we cannot have everything we want. The tighter these constraints are, the less choice we have. Presumably, people feel happier when they are less constrained. However, a MMOG providing too little challenge is not constraining enough, and people get bored quickly. Example/comparison: people prefer a 100-piece puzzle than a 2-piece puzzle. Castronova deduces a function regulating hours of game time for gamers based on the 3 following assumptions:

• People do things that make them feel happier
• confronting and overcoming challenges makes people happy
• higher rewards is preferred, holding challenge levels equal

This function shows several particularities. Gamer can be willing to pay for tougher constraints. Rich people can play because they can afford it. Poor people can play because they are not sacrificing very much income to do so. However, those not rich nor poor may be very sensitive to the impact of gaming time. Some people make money from their virtual activities: there is a substitution between Earth work and game time that depends, to some extent, on the financial rewards available in each. The economic phenomenon emerging is: Game time is a substitute for other consumption goods, and it is also a substitute for work time.

Many actors in the VW market of the future

The development of VW companies of the future can be classified in three domains: connections (Internet, wireless), interfaces (voice chat, body-motion detection) and content (media delivery services, game retailers). A monopoly may emerge because our time in virtual worlds is more valuable if everyone we know is in the same world [see Facebook...] and the more players a VW has, the more attractive it is. However, several reasons limit the possibility of a monopoly:

• People have different tastes, and they go in VW that fulfill their needs. A VW so big it would satisfy everyone would be too expensive to build and maintain.
• Congestion in a VW limits its number of simultaneous users
• It seems players get attached to their avatars as they get stronger and build their stories. However, incentives could be given to switch from a VW to another: in Ultima, you can directly buy your levels; in Camelot, you can start a new avatar at level 20 if you have already gotten one to level 50.
• the star phenomenon widespread in artistic markets: If a company designs a better game, it will attract players

The impact of VW on RL societies

The fact that labour hours that were once producing automobiles are now producing avatars does not mean anything about the level of wealth in society. Online economies do not belong to any country. Hence if economic activities move from RL to VW, countries would seem to be in recessions or depressions because state taxes would not bring as much as they did, and people would still use public infrastructures (roads, social welfare). Poor people may find VW attractive because they could earn more money in them than IRL. It would cost nothing to rich people to travel between RL and VW. New statistics and economic management policies may have to be developed

Who regulates VW economies? At the moment, game companies are not taken as legally responsible by RL law for what happens in their worlds - video games are speech. The EULA and ToS restrict users' rights, and profits drive the company. Hence, some players complain (more or less uselessly) on forum boards after patches and updates. RMT is another governance issue in which companies are the only ones to decide. Buying avatars or items from other players with real money frustrates the players who do not spend money in RMT. But players are not serfs. They have both voice and exit as options for resistance.

Bonus: differences between RL and VW economies

Unlike IRL, in VW ...

• It may make sense to control some prices.
• Players must have something to do or they will be bored: Work is good.
• increases in per-capita wealth [...] will lower the challenge level of the game: Growth can be bad.
• Avatars' abilities can change a lot over time and the number of connected avatars fluctuates.

[Literature] A qualitative study of Ragnarök Online private server in-game sociological issues

Back in November 2009, I mentioned the multiplayer game design issues impacting social life inside RO. The paper has been accepted at FDG2010. You can read the final version.

I conducted interviews and observed players' behaviors in an official server (2000 users at peak time) and two private servers (200 and 2000 users at peak time). On the examined private servers, the social environment and some of the game mechanics were more adapted to players' needs. Examples are:

• a broader choice in avatar customization
• the ability to observe parts of the game world while not being logged-in (the Control Panel)
• less constrained groups
• events and GM taking the player community more into account
• easier XPing (leveling in RO is the main activity, and it's a lot of grinding) thanks to rates and the Warpra+Healer combo
• @commands enabled to players so that they can see who is online, sell merchandises with a character while playing with another and compare prices

Clearly, the Warpra+Healer totally changed the game. Champions could camp the respawn of MVP (boss monsters) and kill them relatively quickly with Asura Strike. This left virtually no end-game challenge for guilds other than the bi-weekly War of Emperium (battles between guilds in castles lasting between two to three hours).

[Literature] Fundamentals of Game Design, ch 1: Games and Video Games

These are my notes for the first chapter of Fundamentals of Game Design, a book by Ernest Adams and Andrew Rollings (pages 3 to 35). I do not know if I will do all of their chapters, but you can expect other posts dealing with this interesting book. [My comments will be inside square brackets.]

What is a game?

Work consists of whatever a body is obliged to do, and ... Play consists of whatever a body is not obliged to do
-- Mark Twain, The Adventures of Tom Sawyer

A game contains rules, goals, play and pretending. [play and pretending bring games close to theater]. Toys have no rules. Puzzles have only one goal but no rules. In some languages like Swedish, playing with a goal and playing without one are two different words.

Interactivity: Games require acive players whose participation changes the course of events. Play is a participatory interactive entertainment. Unlike books or movies which are presentational, ie their content does not change. [What about Gamebooks?]

Suspension of disbelief: The Magic Circle is the playground for pretended reality. However, the distinction between real world and pretended reality is sometimes blurred if events in the game [losing for instance] are meaningful outside of it [death! cf Mesoamerican ballcourt game sacrifices].

Challenge: A game must include challenge [cf Flow Csikszentmihalyi]. Challenge difficulty is perceived differently by players. Gameplay consists of challenge and actions.

Rules: Victory and defeat conditions are not must-have rules. They only make the game more exciting. Metarules are immutable rules that define how which mutables rules can be changed. [cf Morpheus in Matrix: some rules can be bent, others can be broken] [smart metarules make mods possible; this kind of meta-concepts echoes software engineering principles]

Players who are trying to achieve different unrelated goals that are not mutually exclusive are neither competing nor cooperating - they are not really playing the same game [what about AH/bankers/tradeskill players in MMOG? It seems there are different goals players can look for. Are there different games within MMOG (ie different rewards for different actions) or different ways to play the same game (ie same reward for different actions)?]

Symetry and roles: In a symetric game, all players follow the same rules. Fox games are non-symetric games: one player has the fox, the other has the sheep/geese/hounds.

Types of interaction	In simple words	Examples
Single-player	"me versus the situation"	Solitaire
Two-player competitive	"you versus me"	Chess
Multiplayer competitive	everyone for himself" (but agreements between players might be possible)	Monopoly, Diplomacy, Agricola
Multiplayer cooperative	"all of us together"	Shadows over Camelot (without Traitor)
Team-based	"us versus them"	Bridge

Conventional games versus video games

Advantage of video games: With video games, players do not have to control the rules themselves. [In MMOG, Game Masters are often needed, not only for police purpose but also for in-game events] This means more immersion for the players.

Avoid trial and error [that is also a general HCI recommendation: users do not read handbooks. I wonder if "trial and success" could be a relevant game design that teaches the rules to the player. For example, whatever possible action done by the player in the first levels of Plant versus Zombies leads to victory. Even though it is not really a tutorial, the point is only to teach the player what key elements do and the principal game mechanics and actions.]

AI: Players often believe the game contains smart AI. In fact, most of the time, the game only fakes smart in-game characters to entertain the player enough. But sometimes, the magic circle is broken because of AI dysfunction or an unexpected choice from a player. [see for instance a NPC in eXistenZ that stucks the player in a while loop]

Segment: Your game can not please everyone because everyone does not enjoy the same thing. [interestingly, this applies perfectly well to marketing segments]

Gameplay is the primary source of entertainment in all video games. But aesthetics and harmony/coherence matter.

Types of challenge	Video game examples
Physical coordination	DDR, Tetris, Street Fighter
Logic	Mastermind
Pattern recognition	Sonic the Hedgehog (behavior patterns of ennemies), Mahjong
Time pressure	Trackmania, Zuma
Memory and knowledge	You Dont Know Jack, Memory Match
Exploration	Doom, Portal
Conflict	Age of Empires, Pac-Man, Half-Life, ICO
Economic	Civilization, The Settlers
Conceptual Reasoning	The Incredible Machine, Façade, Syberia

Risk implies reward, otherwise there is no incentive to take the risk.

Types of immersion	Examples
Tactical	Tetris trance, the action is so fast the brain has no time to focus on something else
Strategic	Chess master, observing, calculating and planning [you need a player of the same or higher level so that you are not bored]
Narrative	being inside a story, like in good books or movies

Test your skills

Each chapter has a collection of multiple choice questions to let you check if you have learned the biggest points the authors wanted to make. Following the questions, a few exercises and discussion questions bring interesting and inspirational matter about the current chapter. I only give my pick of the best exercises I found in this chapter.

• Create a competitive game for two players and a ball that does not involve throwing it or kicking it.
• Define a competitive game with a single winner, for an unlimited number of players, in which only creative actions are available.
• As a potential designer, do you see yourself as an artist, an engineer, a craftsman, or something else?