Three games that look nothing alike
Tag in a schoolyard. A capture in chess. A trick won at cards. No shared board, no shared pieces, no shared goal.
Underneath, they run the same handful of moves over the same handful of things. This page walks down from familiar mechanics to their parts, then back up — rebuilding the famous ones as compounds of a few primitives. One claim, made runnable: a single data source drives every diagram, so the thesis is demonstrated, not asserted.
Mechanics are verbs
A mechanic is a verb — a method an agent invokes on game state (Sicart). Not the board, not the theme, not the story. The act. Move. Capture. Draw. Bid. Behind a game you already know, a small vocabulary of verbs is doing all the work.
Rules, mechanics, systems
Three words that get muddled. Rules are logic: if X then Y. Mechanics are verbs: what you do. Systems are the nouns the verbs act on — the board, the deck, the economy. Keep them apart and the rest of this page stays sharp.
The descent: what is capture?
Pick a famous mechanic and pull it apart. It was never an atom — it falls into a short, ordered list of reads and writes over a few stores. Step through one and watch the compound come apart.
The table
Here is the whole basis. Five typed stores hold everything a discrete game tracks. Two reads address and test; three write families change state. The centerpiece: Relocate is one operator — Move, Transfer, Transform, Reveal, Advance are the same act over different stores. The typed state-space is the invariant the periodic-table metaphor needs.
The recomposition
Now back up. Every famous mechanic in the gallery is rebuilt from the same parts. Open one and read its sequence of ops over stores. Swap a single step in your head and the name changes under your hands — capture-by-removal becomes capture-by-displacement, a “bump.”
Honest edges
Where the model stops, on purpose. These are features, not gaps — the model declaring its own boundary.
Continuous dynamics
Collision, momentum, aiming, analog timing. The model is honest only over discretized state; below that altitude, physics is a different kind of thing. VGDL and PuzzleScript “handle” it by discretizing — a modeling choice, not a reduction.
Expressive & cognitive play
Observe, deduce, emote, pet the cat. In iff it writes tracked state (the inclusion test); otherwise it is content, presentation, or player cognition.
Presentation / operational logics
How an operation is shown — juice, feedback, communicative coupling — is a genuinely orthogonal axis. Folding it into the primitives is what costs other frameworks their minimality, so we keep it out and name it here.
Skill vs. chance
How a gate or a randomize resolves — player mastery vs. alea — is a quality of outcome-determination that sits slightly aside from the op itself.
The basis itself
Five stores — not three, not seven — is a defensible choice at the discrete altitude, not a theorem. “Relocate over Time” (ending a turn) writes a phase value that arguably lives in Attribute; Visibility may likewise reduce to Attribute plus a quantifier over who-can-see. The table earns the periodic-table metaphor by being useful and minimal here — not by being the one true partition of play.
The deeper map
For the curious: a dozen frameworks — Sicart, MDA, Machinations, Caillois, Koster, Ludii, VGDL, PuzzleScript — plotted on one ladder of primitive → pattern → system class. The lesson: most apparent disagreements between them are altitude mismatches, not disputes about games. (interactive cross-walk — next pass)
A periodic table at one altitude, a molecular chemistry above it, an ecology above that. The mistake was asking one layer to do all three jobs.