Coop Chaos

What it is. Two-to-four players share one escalating task — a kitchen, a ship, a factory — where the work outpaces any single pair of hands. Success needs division of labour, hand-offs, and constant talk; the joyful friction between players is the product. Extension beyond FUN.md’s 21 genres.

Player fantasy. “We did that — barely.” The shared adrenaline of a near-miss pulled off by shouting the right thing at the right second; a story you tell afterward, together.

Pillars

Communication forced by design. The layout, not the rules, makes players talk — split resources, blind hand-offs, a task no one can finish alone. If silence works, it isn’t coop chaos.
Escalating shared load. Difficulty is throughput the table demands vs the throughput the players can coordinate. The clock and the order queue ramp; the kitchen literally shifts under them.
Legible chaos. However frantic, every station, order, and hazard reads at a glance. Chaos you can’t parse is noise; chaos you can just barely parse is fun.

The loop stack

Scale	The beat
Moment	Grab → carry → hand off → place; one micro-task, contested by space and time.
Encounter	A level/round: fulfil an order queue before the timer, as a layout fights you.
Session	A run of levels; escalating kitchens; star thresholds gating the next.
Meta	Unlocked levels/tools/modifiers; co-op star totals; the campaign map.

Essential systems

System	Why it’s load-bearing
`system-coop-and-competition`	Interdependence is the core — design tasks no one player can solo.
`system-difficulty-and-dda`	The order-rate ramp and the layout-shift are the difficulty; scale to player count.
`system-encounter-design`	A level is composed pressure + pockets; the moving hazard IS the encounter.
`pattern-pacing-and-tension`	Deliberate breather beats between order surges; the finale is the peak.
`system-session-structure`	Short, replayable rounds; the run shape that suits couch play.

Content & difficulty model

Difficulty = required throughput vs coordinatable throughput. State it as an inequality (orders/min the queue demands ≤ what N coordinated players can serve) and tune the queue against it (FUN.md law 3).
The layout is the level. Author kitchens/ships/rooms, not enemy stats. A moving hazard (a splitting kitchen, a rising tide) is a pacing device — treat its rhythm like a tower-defense wave curve: surges with breathers, finale peaks.
Scale to player count deterministically. Task volume and station count key off N; the same seed with 2 vs 4 players must both be winnable and both replay.
Null-coordination loses. The scripted “everyone works solo, no hand-offs” run must fail the level — that’s the proof the design actually forces coop.

Signature-mechanic seeds

Overcooked but the recipe is hidden and only one player can read it — the forced channel is information, not just hands (constraint; composes genre-narrative-decisions for the reader’s dilemma).
Overcooked but on a train you build ahead of yourselves — the workspace is also a shared build task (mechanic-swap; the Unrailed bend).
It Takes Two but the two mechanics can jam each other — interdependence sharpened to interference (mechanic-swap; composes system-counter-systems).
Overcooked but asymmetric roles: one cooks, one defends the kitchen — a coop-chaos/tower-defense blend (structure; composes genre-tower-defense).
Coop chaos but the tasks are secretly competitive — shared kitchen, private scores (tonal; composes system-coop-and-competition‘s rivalry hooks).

Common pitfalls

Silence wins. If a good solo player can carry, the coop is decorative. Force hand-offs and split resources so talking is mandatory.
Illegible frenzy. Too many simultaneous hazards and the chaos stops reading; players fail without understanding why. Cap concurrent threats; keep salience.
Punishing the weaker player. Chaos that scapegoats one player kills the couch. Design shared blame — failure should feel like our miss.
Wall-clock timing. Order timers and layout shifts must run on sim time, not Date.now, or replays and goldens lie (FUN.md law 6).

Anchors

anchor-overcooked — communication-forced-by-design; escalating kitchens; the canonical coop-chaos loop.
anchor-it-takes-two — asymmetric coop set-pieces; a new interdependent mechanic per chapter.

Verify — extension note

Coop chaos is an extension; it has no dedicated FUN.md section, so it composes the verify patterns of its parents:

Wave/pressure pacing → FUN.md §8 — Tower defense: gate the order-queue/hazard curve on “each surge breathes, finale peaks,” not monotonicity. This is the primary proof.
Encounter containment → FUN.md §4 — Action-adventure: keep hand-off lanes / exit rows clear; assert no station softlocks.
Skill-delta → FUN.md law 2: a coordinated bot script clears; the null-coordination script fails. Determinism and cosmetic-view rules apply unchanged (laws 6–7).

Composes with

system-coop-and-competition — the interdependence toolkit; this genre is its loudest expression.
system-difficulty-and-dda — scale pressure to player count and skill.
pattern-pacing-and-tension — the surge/breather rhythm that keeps chaos joyful.