Reward Schedules — Drops, Chests & Ethical Compulsion

What it is. The schedule on which the game pays out — fixed (every N), or variable-ratio (random, averaging N). Variable-ratio is the most powerful reinforcement pattern known, which is exactly why it demands an ethical hand. This module is about wielding its grip to make earning thrilling — and refusing its use to extract.

Player fantasy / why it’s fun. “Maybe this one.” Anticipation is the reward; the drop is the payoff. Uncertainty makes a trivial input (Peggle’s last peg, opening a chest) feel enormous (anchor-peggle, maximal juice on trivial input).

When to use / when NOT

Use it when	Skip it when
Loot/drops are a core reward channel	Rewards are deterministic and that’s the point (puzzle clears)
Anticipation itself is fun (chests, gacha-of-cosmetics)	The randomness would gate required progress unfairly
You want surprise to punctuate a grind	It’d become a slot machine dressed as a game

The honesty line. Variable-ratio is fine for cosmetics, flavor, and bonus rewards where the base game is complete without them. It becomes a dark pattern when it gates required power behind paid randomness, hides odds, or engineers loss-aversion (streaks you’ll “lose”). Design compulsion you’d be proud to explain.

Variants

Variant	Schedule	Feels like	Watch for
Fixed-ratio	Reward every N	Reliable, plannable	Predictable → less exciting
Variable-ratio	Random, averages N	The slot-machine pull	Ethics; the honest use is cosmetic/bonus
Fixed-interval	Reward every T time	Daily-login cadence	Retention manipulation if punitive
Pity / bad-luck protection	Guaranteed by attempt N	Fairness floor on RNG	Always add this to variable-ratio
Tiered / weighted	Common→rare distribution	Chase the rare	Odds must be shown
Deterministic reveal	RNG resolved, shown honestly	Trust	This is the ethical default

Tuning levers

Lever	What it controls	Healthy range / rule
Base rate	How often you pay out	Frequent small + rare large — a steady drip with peaks
Variance	How swingy	Enough surprise to thrill; not so much it feels arbitrary
Pity timer	The fairness floor	Mandatory on any variable-ratio — guarantee by attempt N
Odds transparency	Whether players know the chances	Show them. Hidden odds are a dark pattern, full stop
What’s behind RNG	Cosmetic vs required power	Keep required progress off the random schedule
Anticipation window	The pause before reveal	Long enough to build tension, short enough not to annoy (`pattern-juice-choreography`)

Dark patterns to refuse

Hidden odds — never. Publish them.
Pay-to-random for power — required strength behind a paywalled RNG box.
Loss-aversion engineering — “your streak resets in 2h” pressure.
Near-miss manufacturing — faking “so close!” reveals to bait retries.
FOMO scarcity — artificial time-limited rarity to force impulse.

Compulsion is a tool; extraction is a choice. The Codex’s stance: use anticipation to reward engagement, never to punish disengagement.

How it wires to Hayao

RNG is sim, through world.rng. Every drop rolls on world.rng — never Math.random (CLAUDE.md invariant 2). This makes the whole schedule deterministic per seed: a golden run hashes identically, and you can audit the payout distribution in a test.
Resolve, then choreograph. The sim resolves the drop instantly and returns the reveal as choreography; the view plays the chest-open, the flash, the rarity color (LAYER_HUD, cosmetic = true) — deletable without changing the outcome ([[FUN.md law 6]]). The anticipation is view time over sim truth, like match-3’s cascade script ([[FUN.md §13]]).
Audit odds and pity in CI. Roll N drops over seeds; assert the empirical distribution matches the stated odds and that pity fires by attempt N — the same “intent honesty” audit deckbuilders run on telegraphs ([[FUN.md §11]]).
Prove the base game is complete without the RNG — a bot that never opens a random reward still clears the game. That’s the ethical proof.

Fails when…

No pity floor. Pure RNG can strand a player for hundreds of attempts — cruel. Always cap it.
Hidden or lying odds. The distribution doesn’t match the shown numbers — an auditable, shippable-blocking bug and an ethics failure.
Required power behind RNG. Progress gated on luck (or a wallet) — the game is now a slot machine.
Reveal fatigue. Anticipation windows so long or frequent they annoy — tune the pause.
Reward inflation. Everything’s legendary → nothing is. Rarity needs scarcity (system-economy inflation).

Verify

Odds/pity distribution audit over seeds (intent honesty): [[FUN.md §11]].
Determinism per seed (golden hash of a drop run): [[FUN.md law 7]].
Reveal is cosmetic — sim resolves, view replays, hashes equal: [[FUN.md law 6]].
Base game clears without opening any random reward (a null-reward baseline): [[FUN.md law 4]].

Composes with

system-economy — drops are a faucet; rarity is inflation control.
system-collectibles — variable-ratio drives set completion.
system-meta-progression — the meta ledger fed by run rewards.
system-procgen-design — seeded randomness shares the same rng discipline.
pattern-juice-choreography — the anticipation→reveal is pure choreography.
pattern-risk-reward — push-your-luck chests turn the schedule into a decision.