Laboratory & coin-op

Four mechanics in this window, and two of them are load-bearing for everything else. Spacewar! contributes Object Collision As Verb in 1962 — two things occupy the same space and something happens — which is the direct ancestor of hit points, combos, ragdolls, destructible walls, and line-of-sight detection. Pong then contributes three at once in 1972: Single-Screen Arena, where the frame is the entire world; Numeric Score, the first thing a game ever remembered about a player; and Same-Screen Two-Player, which remains the most legible multiplayer arrangement anyone has built. Notice what is absent. No persistence beyond the session, no fiction, no camera worth naming, no economy other than the coin. Games in this period are being defined by what the hardware can hold rather than by what anyone wants to say, and the mechanics that survive are the ones cheap enough to compute in real time. Gun Fight, Breakout, Night Driver, and Combat all appear here as adopters rather than originators, refining collision into recognizable forms.