> For the complete documentation index, see [llms.txt](https://countertrade.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://countertrade.gitbook.io/docs/battles/room-formats.md).

# Room formats

The battle formats — 1v1, 5-player, 10-player, 5v5 team, and Open Arena — with their seat counts, minimums, and prize splits.

A room's format sets how many traders compete, how the winner is decided, and how the prize pool is split. The prize pool is the pooled entry fees for that room, minus the platform fee. Every trader in a room starts with the same paper balance. In four of the five formats you are ranked on your own ROI; in a 5v5 room your side's combined result decides it.

| Format                 | Seats               | Runs with            | Who wins                          | Prize split                                                  |
| ---------------------- | ------------------- | -------------------- | --------------------------------- | ------------------------------------------------------------ |
| 1v1 duel               | 2                   | 2                    | Top ROI                           | Winner takes the whole pool                                  |
| 5-player free-for-all  | 5                   | 2 or more            | Top ROI                           | Winner takes the whole pool                                  |
| 10-player free-for-all | 10                  | 3 or more            | Top 3 by ROI                      | 60% / 30% / 10%                                              |
| 5v5 team               | 10 (two teams of 5) | 10 — both sides full | Team with the higher combined PnL | Winning team splits the pool equally                         |
| Open Arena             | 50 to 1,000         | 10 to 100, by size   | Top ROI                           | Top places share the pool; entry may be a refundable deposit |

**Seats** is the maximum the room holds; **runs with** is the minimum it needs by the join deadline. A room that falls short of its minimum is cancelled and every entry fee becomes refundable, so a 10-player room that draws four players still runs — with four.

## 1v1 duel

Two traders, head to head. The higher ROI at the end takes the entire prize pool. On the create screen and the Battle Hub cards this format is tagged **DUEL**.

## 5-player free-for-all

Up to five traders compete individually, and it runs with as few as two. The single top finisher by ROI takes the whole pool. Tagged **SQUAD** on the format cards — this is just the format's label and is unrelated to the separate squads feature.

## 10-player free-for-all

Up to ten traders compete individually, and the top three by ROI share the pool: **60%** to first, **30%** to second, **10%** to third. It needs at least three players to run, since three places have to be payable. Bigger field, bigger pool, higher variance. Tagged **ARENA**.

## 5v5 team

Ten traders split into two sides of five. Each side's result is the **combined PnL** of its members, and the side with the higher total wins. The whole prize pool is then split **equally** among the five traders on the winning side, regardless of who on that side scored best. When you join a 5v5 room you pick a side (**Join Side A** / **Join Side B**), and both sides must be full for the room to start. Tagged **VERSUS**.

## Open Arena

A mass-participation free-for-all, much larger than the other formats: arenas are sized at 50, 100, 250, 500 or 1,000 seats. You can't create one — arenas are run by CounterTrade, so you'll only meet one that already exists. Its button reads **Register** rather than Join.

Ranking is by ROI, as in the other individual formats, and the top places share a prize pool. How many places pay scales with the size of the arena — the top 10 in a 50-seat room, the top 100 in a 1,000-seat one — with the largest share at the top and progressively smaller bands beneath it. That paying depth is also the minimum the arena needs to run: one that can pay 25 places needs 25 players, so every paid rank provably exists.

What differs from the other formats is what your entry is. An arena runs one of two ways, and the arena's own rules tell you which:

**A normal entry fee.** The pooled fees become the prize pool, minus the platform fee, exactly as in every other format. You pay to compete, and only the paying places get anything back.

**A refundable deposit.** Your entry comes back to you at settlement rather than being competed for — it is there to make holding a seat cost something, not to fund the prizes. The default is 5 USDC, set per arena. Under this arrangement there is no platform fee, and there cannot be: a fee would be carved out of the same escrow the deposits sit in, so they could no longer be returned in full. The prize on top comes from what the arena's organizers put up, and from any deposits that were not earned back.

The difference is visible in what you receive. In a deposit arena a payout equal to your entry is your deposit coming back; anything above it is prize on top. In a fee arena every payout is prize.

Deposit arenas were introduced for sponsored events, where the prize is funded by the organizer rather than by the field — which is what lets an arena be effectively free to enter and still pay out.

## Related

* [How battles work](/docs/battles/how-battles-work.md)
* [PnL and ROI](/docs/trading/pnl-and-roi.md) — how ROI, the ranking metric, is calculated
* [Claims and refunds](/docs/funds-and-settlement/claims-and-refunds.md)