# Fee Structure

Every game in the SSE ecosystem follows a consistent fee routing pattern with game-specific ratios.

## Fee Destinations

| Destination  | Wallet                     | Purpose                                       |
| ------------ | -------------------------- | --------------------------------------------- |
| Winners Pool | Player wallets             | Game-specific payouts to winners/contributors |
| Treasury     | `GameState.treasury`       | Protocol revenue                              |
| Buyback      | `GameState.buyback_wallet` | $SIMULATION token buyback                     |
| Rollover     | Vault PDA (internal)       | Next round's starting pool                    |
| Liquidity    | Friendly Pools             | LP provision for $SIMULATION                  |

## BPS Calculation

All games use basis points (BPS) for payout calculation. 10,000 BPS = 100%.

All arithmetic uses checked operations to prevent overflow. If any calculation would overflow a `u64`, the transaction fails with `MathOverflow` (error 6004).

## Alon's Box Fee Splits

### Settle (Winner Found)

```
pool = total_deposits + rollover_in
```

| Recipient | BPS              | Percentage | Formula                               |
| --------- | ---------------- | ---------- | ------------------------------------- |
| Winner    | 5000             | 50%        | `pool * 5000 / 10000`                 |
| Evidence  | up to 3000       | up to 30%  | Sum of `evidence_amounts[]`           |
| Treasury  | 500              | 5%         | `pool * 500 / 10000`                  |
| Rollover  | \~15% (residual) | —          | `pool - winner - evidence - treasury` |

Evidence payouts are flexible within the 30% cap. Unused evidence allocation is added to rollover. Rollover is computed as a **residual** (subtraction), capturing all integer-division rounding dust.

### Expire (No Winner)

Payouts are based on **`total_deposits` only** — previous rollover is fully preserved.

| Recipient      | BPS                | Percentage | Formula                               |
| -------------- | ------------------ | ---------- | ------------------------------------- |
| Buyback        | 4750               | 47.5%      | `total_deposits * 4750 / 10000`       |
| Treasury       | 500                | 5%         | `total_deposits * 500 / 10000`        |
| Rollover added | \~47.5% (residual) | —          | `total_deposits - buyback - treasury` |

New rollover = old rollover + rollover added. The `rollover_added` is computed as a residual to absorb rounding dust.

### Explicit Rollover Tracking

Rollover is tracked explicitly in `GameState.rollover_balance` rather than derived from the vault's lamport balance. This means:

* Unsolicited SOL transfers to the vault are ignored by game math
* Vault balance invariant: `vault_lamports = rollover_balance + rent + active_deposits`

## SSE Prediction Rounds (Suggested)

| Recipient                  | Share  |
| -------------------------- | ------ |
| Winners Pool               | 85–90% |
| Platform Fee               | 5%     |
| Liquidity / Friendly Pools | 5%     |

These values are configurable per game. See [Actions and Economy](https://simulation-theory.gitbook.io/simulation-theory-docs/alons-box/actions-and-economy) for Alon's Box payout details with worked examples.