Placing bets

Placing is a single on-chain call per bet: approve USDG once, then placeStrike, placeRange, or placeLadder 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	Ladder	`payouts[]`, `massWad[]`

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` / `maxStakeCap()`
`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 for none
`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 the liability cap.
Ladder — 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. See Bet constraints.

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