Trade a duel

Every duel has a trade panel: on a computer beside the duel, on a phone behind the Buy buttons at the bottom of the screen. It works like Uniswap's swap widget: what you pay above, what you receive below, and a button between them that flips the two.

Three trades

Pick the asset of each field from its menu, which also shows what your wallet holds. Picking the asset of the other field swaps the two fields, as on Uniswap.

With default terms, trades against ETH pay 1.2% in ETH, and a switch through ETH pays on both legs. A direct A/B switch instead burns 0.5% of the token you leave. The panel quotes both routes and takes the greater net output; it shows the route and the duel’s actual fee terms. See Fees.

Before you confirm

• You receive is a quote from the Uniswap V4 Quoter: what the swap would give right now, fees included.
• Slippage (Auto at 2%, a preset, or a custom value up to 50% in the settings) sets the minimum output you accept. If execution would return less, the swap fails. The deadline is 10 minutes by default, adjustable up to 3 hours: inclusion after it fails, but it does not cancel a pending transaction. A failed transaction can still cost network gas.
• Price impact compares the quote with the pool’s current price. The details under the quote show the rate, minimum received and fee.

Large trades

Past 5% price impact, the button turns red; past 15%, it asks for a second tap. A large trade can move the price substantially. If the subsequent realignment runs, it can partly offset that move and capture profit for the pot. Selling straight back may return much less than you paid; the absence of a holding lock does not guarantee available liquidity.

Selling all of a side

An ETH pool can hold less ETH than its side's holders could ask of it: after each purchase, the realignment sells into it tokens taken from the pool between the sides, and the ETH they fetch goes to the other side's pool. Selling everything at once can then bring the pool back to its launch price before every token is sold. The Duel router sells the rest in the same transaction: into the same pool once the realignment after the sale has bought those tokens back, then what it could not buy back through the pool between the sides into the other side's ETH pool, where their ETH went. The panel quotes the whole sale, and names what would stay in your wallet only when the other side's pool cannot pay for it either.

Approvals

Buying with ETH needs no approval. Selling or switching a side's token takes one transaction too: your wallet first asks for a signature, a permit (EIP-2612) that lets the Duel router move exactly that amount, then for the trade, which uses it. The signature approves the token and nothing else: the price, the minimum received and the recipient belong to the trade, which you confirm next. A contract wallet (a Safe, say) cannot sign a permit the token accepts: it approves the router with a transaction instead, once per token, as anyone can choose to by turning off Approve by signature in the swap settings. If the trade fills only in part (the pool moved meanwhile), the rest of the permit stays approved for the router. The router only ever pulls tokens from the wallet that sends the swap.

In the first seconds

With default launch terms, for 10 seconds after a duel launches, buys pay an anti-snipe tax that starts at 98% and halves at least once a second. The trade panel shows it while it lasts. Waiting a few seconds is almost always better.

Other ways to trade

Duel's pools are ordinary Uniswap V4 pools with a hook: any V4 router, terminal or aggregator can trade them, and the hook applies the same fees and rules whoever routes the swap. Only the Duel router sells in several passes: through another router, a sale bigger than what its ETH pool can pay for stops at the pool's launch price, and the rest stays in your wallet. See Build on Duel.