Challenges
Pick a side on a two-way market and challenge someone you follow, or who follows you, to take the other for the same stake. When the market settles, whoever's right wins.
Sending one
From a profile (Challenge) or the call panel (“Challenge a friend on this”). You choose the stake and they match it. Your side is backed when you send, so it's a real position from that moment. Theirs is backed when they accept, at the price then. Both sides need at least a 10% chance, so it's a real contest. Five-minute rounds can't be challenged. You can send five a day and have ten waiting for an answer.
Answering
The other person gets a notification and can accept or decline. If they decline or don't answer, your position stands as an ordinary call. Challenges nobody answers expire after seven days, or when the market settles, whichever comes first.
Settling and XP
An accepted challenge settles with the market and each side's shares pay out as normal. The winner also earns XP like a right call on their side, about 10 ÷ its chance when the challenge was sent, up to 100, and the head-to-head point. Records against each person show on every challenge between you. Challenges carry no prize from Backd.