Placing bets

Placing is a single on-chain call per bet: approve USDG once, then placeStrike, placeRange, placeTieredBetter, or placeShuffle on ChancePool. Full signatures live in Contract methods; this page covers how to build the args correctly.

Choose a mode

Your game	Mode	You provide
Double-or-nothing, crash-style multiples	Strike	`multipleBps`
”Always pays something” bands	Range	`payoutMin`, `payoutMax`
Dice, wheels, prize tables - any discrete distribution	TieredBetter	`payouts[]`, `massWad[]`
Pick seats, entropy shuffles the prizes	Shuffle	`payouts[]`, `pickIndexes[]`

See Bet modes for the payout math of each.

Common args (all modes)

Arg	How to build it
`stakeAmount`	USDG units; must clear `minBet` / `maxBetAmount` / `maxBetCap()`
`clientSeed`	32 random bytes, non-zero. This is the player’s entropy contribution - generate it client-side and keep it so users can verify fairness later
`expectedCommitId`	Read `currentCommitId()` right before sending (see below)
`affiliate`	Optional affiliate address; zero address stores `feeRecipient`
`platform` / `game`	Optional attribution strings, ≤ 64 bytes each (empty string = unset)

Keep expectedCommitId fresh

Every bet pins the epoch it settles under. If the epoch rotates between your read and your transaction landing, the place reverts CommitMismatch. The fix is mechanical:

TypeScript

async function placeWithRetry(place: (commitId: bigint) => Promise<Hash>) {
  for (let attempt = 0; attempt < 2; attempt++) {
    const commitId = await readCurrentCommitId()
    try {
      return await place(commitId)
    } catch (err) {
      if (!isCommitMismatch(err) || attempt === 1) throw err
    }
  }
}

There is no epoch max-age: an open epoch stays placeable until the keeper rotates it.

Mode-specific gotchas

Strike - multipleBps is gated by the live effectiveMaxMultiplierBps(), which shrinks as bankroll liability fills. Quote it immediately before placing, not at page load.
Range - the band must bracket expected value: payoutMin ≤ 0.85 × stake ≤ payoutMax, and payoutMax − stake must fit both the liability cap and Kelly.
TieredBetter - the contract checks Σ massWad × payouts / WAD == EV × stake in exact integer math. Snap your float probabilities onto the identity (largest-remainder rounding, then move single mass units between buckets until the check passes) or the place reverts InvalidOdds. Preview with validateTieredBetter. See Bet constraints.
Shuffle - snap payouts so Σ payouts · K == N · EV × stake. Picks must be distinct and in range. Preview with validateShuffle.

Attribution

platform and game land on the BetPlaced event (emit-only - never stored on the bet, and echoed back through the API’s bet payloads). Pass stable identifiers so your wagers are attributable in analytics:

Field	Example
`platform`	`chance.money`
`game`	`dice.chance.money`

After the transaction

The betId comes back as the return value and on BetPlaced. From here, follow Results & proofs - you don’t need to poll the contract.

Quickstart

Integrate

SDK

Staking

CHANCE token

Choose a mode

Common args (all modes)

Keep expectedCommitId fresh

Mode-specific gotchas

Attribution

After the transaction

​Choose a mode

​Common args (all modes)

​Keep expectedCommitId fresh

​Mode-specific gotchas

​Attribution

​After the transaction

Choose a mode

Common args (all modes)

Keep expectedCommitId fresh

Mode-specific gotchas

Attribution

After the transaction