The cap that was already gone
A month after the PvP lives system replaced the 40-word duel cap and the single-collision ending, the glossary and architecture docs still described the old rules.
The glossary still said AI duel and PvP duel each capped a player at forty words, and that any collision ended the game outright with the higher score winning. Neither claim had been true for a month, since the PvP lives system shipped and removed the word cap from both modes entirely. In PvP it also replaced the instant collision-ending with a life system: two lives per player, a collision costs one, and only losing the last one ends the game. AI duel kept its original rule, first collision ends it, higher score wins, since a solo game against the AI has no opponent for a life system to matter against. The prose describing all of that never caught up with the code.
Fixing it meant rewriting the duel entries in the glossary and every architecture diagram that touched a collision or a word count: two sequence diagrams, a state diagram, and a flowchart, seven stale references in total. The daily challenge’s own twenty-word limit was untouched throughout, since nothing about it had changed.
-A game-ending event in which the snake's head enters an occupied or out-of-bounds cell — wall, own body, or opponent snake.
+An event in which the snake's head enters an occupied or out-of-bounds cell — wall, own body, or opponent snake. Always ends the daily challenge and **AI duel** immediately; in **PvP duel** it costs a **life**, ending the game only when the losing player's final life is lost.Rewriting the PvP state diagram into two branches, collision with lives remaining against collision that ends the game, left one older diagram behind: a joining-flow flowchart earlier in the same document that still implied every collision ended a PvP game outright. An automated code review finding caught the contradiction between the two diagrams before it shipped, and a second pass fixed the flowchart and folded in a version bump the first pass had missed.
Writing a precise definition for a collision meant naming a life for the first time in the glossary, which is when it became clear the lives system had shipped without ever getting a glossary entry of its own. Two lives per player to start, no upper cap on how many a player can hold, restored one at a time by a heart. A heart is worth zero points on its own, spawns once for the first player to cross each two-thousand-point milestone, and carries none of a combo fruit’s provenance, since nothing about picking it up is combo-triggered. Both terms exist in the glossary now.
None of the seven stale references was wrong when it was written; they went stale the moment the lives system shipped and stayed that way until something forced a second look. That is the ordinary failure mode for documentation next to fast-moving gameplay code: nothing breaks a build when a sentence stops matching the system it describes, so it waits for a reason to be reread.