Combo String / Cancels — Design Codex

What it is. A string is a sequence of attacks where the recovery of one is cut short — cancelled — into the startup of the next, so hits chain faster than they could stand alone. Depth lives in which moves cancel into which.

Player fantasy / why it’s fun. The fluency climb. Early on you mash and things die. Later you see the string in your head — light, light, launcher, cancel-into-special — and your hands catch up to your intent. The move you couldn’t do last week is muscle memory now.

The verb

Press attacks in an order and rhythm; the system reads the current move’s state and lets you interrupt its recovery into a permitted follow-up.

How it feels / why it’s fun

Legibility of skill. A combo is a sentence the player composes. Watching a good one reads as intent, not luck — the pattern-mastery-and-flow payoff.
The cancel is the dopamine. Cutting recovery you felt was locked is the micro-thrill; it’s the moment the floor drops away and depth opens.
Floor and ceiling in one input. Mash produces a valid (weak) string; precise cancels produce the strong one. Same buttons, wildly different output — the definition of a healthy system-mastery-curve.
Whiffs teach. A dropped combo is legible feedback: you know which link you missed. See pattern-feedback-loops.

Tuning levers

Lever	What it controls	Sane default
Cancel window	Frames where a follow-up is buffered/accepted	6–10 frames (~100–160ms)
Input buffer	How early the next input registers	3–5 frames — generous keeps the floor
Gatling vs strict link	Auto-cancel on hit vs. frame-perfect manual	Gatling for the floor, strict links for the ceiling
Combo scaling	Damage falloff per hit in a string	10% decay/hit, floor at 30% — kills infinites
Cancel routes	Which moves link into which	Sparse graph; not everything cancels everything
Mash tax	Does mashing degrade the result?	Yes — mash gives 60% of optimal, never 0%
Reset on whiff	Miss a hit → string ends?	Yes; landing hits is the earned reward

The one rule: the ceiling is routes and timing, never button count. If the optimal string is just “more inputs,” you have antipattern-false-depth, not depth.

Slots into

genre-fighting-game — the home turf. anchor-street-fighter is the canon: gatling normals into special-cancels into supers, with strict links gating the top play.
genre-action-adventure and genre-soulslike-adjacent hack-and-slash — anchor-hades weaves attack + dash-cancel + cast into fluent loops; anchor-dead-cells rewards weapon-swap cancels.
genre-roguelike combat where system-build-diversity rewrites which routes exist per run.
Pairs naturally with mechanic-lock-on (keeps the string aimed), mechanic-dodge-roll and mechanic-parry (defensive cancels), and mechanic-dash as the universal cancel.

Twist seams

Combos but each hit changes the next available move (emergence) — no fixed routes; every landed hit deals a hand of possible follow-ups (element, position, target-state). The string is discovered mid-fight, not memorized. Leans on pattern-emergence and turns system-status-effects into the grammar.
Combo but the string is the same across all players and coop shares it (perspective) — one canonical string, but two players own alternating links; the cancel window only opens if your partner set it up. The combo becomes a duet, a system-coop-and-competition handshake — see anchor-it-takes-two, genre-coop-chaos.
Combo but dropping it is the mechanic (subversion) — the “correct” string self-destructs at the last hit; mastery is knowing where to stop and cancel into defense. Risk-reward on every extension (pattern-risk-reward).

How it wires to Hayao

State machine, deterministically clocked. Model each attack as a state with startup / active / recovery frame counts and an explicit set of legal cancel targets. Advance on the fixed sim tick so windows are frame-exact and identical across replays — never wall-clock.
Buffer the input, don’t poll the frame. Store the last input with its tick stamp; on entering a cancel window, consume a buffered input if it’s within the buffer horizon. This is what makes the floor forgiving without loosening the ceiling.
Combo state is sim state. The active string, hit count, and scaling multiplier belong in the hashable world state, not the view. Hit-sparks, screen-shake, and freeze-frames are cosmetic view — read pattern-juice-choreography for the split.
Prove the routes. Model the cancel graph as data and assert its properties (no infinite loop, every route terminates, scaling floors out). Study the parts in isolation before wiring the whole — the sandboxes/ labs are the reference for a single mechanic; examples/sokoban/ for the pure-logic/view split.
Feel, timing tolerance, and cancel-window generosity are verified against design/FUN.md — design the routes here, prove the feel there.

Fails when…

The floor is a cliff. Nothing works until you hit frame-perfect links → antipattern-difficulty-cliff. Mash must always do something.
One route dominates. A single optimal string trivializes every fight → antipattern-boring-optimal. Rotate what cancels via enemy system-enemy-archetypes or per-run system-build-diversity.
Infinite loops. No scaling, no whiff-reset → the game solves itself. Combo scaling is not optional.
Depth is fake. Longer strings for the sake of length, no decision inside them → antipattern-false-depth.
The buffer lies. Input registered but ignored, or window inconsistent tick-to-tick → antipattern-input-lie. This is a trust wound; it reads as your failure when it’s the system’s.
Unreadable. Cancels bury the animation so hard the player can’t parse the state → antipattern-unreadable-juice; also breaks pattern-readability.