Adams defined bottom-up game design in 2004 as
turning a simulation or a real-life mechanism into a game. It assumes that
any process that is subtle or interesting to program is also going to be interesting to play with. If the simulation has too many variables, many of them end up being useless, and this results in possible dominant strategies and the game being dull.
Lopes and Kuhnen redefined
bottom-up game design in 2007, as applying a particularly fun gameplay verb or mechanic, complementing it with the appropriate setting, content and story. Developers think first about the elementary game actions, called verbs, that the player can execute (move, attack, ...) and then about the aesthetics (fantasy universe, ...). Examples are games in the Doom series, which were
built barely as excuses for the brutal, over-the-top shooting gameplay; the oppressing universe and mood simply fit well with the gameplay.
In 2010, Deleon focused more on the medium constraints with his definition:
concept inspired by or chosen partly by its form of representation. For instance, Bubble Bobble is about shooting a ball into balls of similar color, and the little dragons or fruits are merely decorations. Same for Bejewelled. Bottom-up designed games also include games made for particular platforms with limited hardware (like Bogost's games for the Atari 2600).
More theory: ludemes
Ludeme was a term coined by Berloquin or Dawkins in the early 1970s, as a portmanteau of
ludic meme, because a ludeme can be found in many (classes of) games. Ludemes are described by Parlett as
conceptual elements of the game, most typically equivalent to its "rules" of play. For example, whereas the material piece shaped like a horse and designated "knight" is a component of the game, the distinctively skewed move of a knight is a ludeme of the class "rule of movement". But other types of ludemes also exist. For example, the name, referend and associated connotations of "knight" - those of a chivalric courtier - may be said to constitute a thematic ludeme.
At GDC 2005, Koster presented his vision of a grammar of gameplay, referring a lot to ludemes. For Koster, ludemes are atomic mechanics with at least 2 possible outcomes (e.g. moving a Checker piece to capture, prepare, or force the opponent to capture (which is actually a kind of preparation)), among which at least one is failure (even if failure only means closing some of the player's opportunity doors). Synonyms of ludemes are: verbs (Crawford), choices (Meier), or conflict. Each ludeme involves a UI action (e.g. pressing button). In terms of complexity, Chess is more complicated than Checkers because each of the 6 types of Chess pieces has its own movement and capture ludemes, while all Checker tokens have the same ludemes.
Bottom-up game design in practice
As Lopes and Kuhnen pointed out, designing games with a top-down approach is somewhat of a dark art when it's time for the designer to bridge the gap between the high-level concept (e.g. in terms of experience, emotions and feelings targeted to the player) and the routine tasks of the player (e.g. drawing a card, moving their avatar or attacking). Current game design textbooks such as Adams' Fundamentals or Schell's Book of Lenses, putting forward player-centricity, suggest a top-down approach by focusing on the experience the entire game should convey to the player.
But a player-centric bottom-up approach is also possible. I'm trying here to provide prescriptive rather than proscriptive steps. In the bottom-up process, the designer should ask the following questions:
- What are the elementary actions the player can do? (define the ludemes)
- How can these actions be fun? (feeling of latent power, fiero, schadenfreude, aesthetic pleasure, ...)
- What are the transitions between these actions? (for the ludeme "roll a dice", it is when the dice is rolling)
- How fun are the transitions? (surprise, feeling of progression)
- Sanity checks: how do the actions fit together as a whole? (pointing to shoot in FPS should not be followed by a dice roll, the intense mechanical ludemes of Doom should be matched with horror-aesthetics ludemes such as the lack of light, ...) Does the overall feel of the game match the feeling of all the elementary actions put together? (ludemes should add up, not negate each other)
This process is tentative, possibly flawed, and therefore feedback is most welcome.