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Duels

1v1 and 2v2 races on a problem or bug hunt, matched by rating or by room code, both sides live and settled by the judge. Wins pay XP and rating. Unlimited.

How do CodeKairo duels work?

The duels page is the lobby: queue for a public 1v1 or 2v2 on a random problem or bug hunt, or open a private room with a six-character code for friends. Matching starts at ±200 rating and widens by 100 every ten seconds; a public duel nobody joins is dropped after 20 minutes, a private room after two hours. In the arena both sides see the other's runs and tests passed; the first accepted submission wins. There is no time limit — a duel lasts until someone solves it or forfeits — and if the other side leaves and stays gone for two minutes, the side that stayed can claim the win. The page shows your live duel, your last ten and a win/loss record. Unlimited on every plan; reading the page needs no account, duelling needs a free one.

How it works

  1. Pick a mode. 1v1 or 2v2; a problem or a bug hunt. Teams fill in join order.
  2. Queue, or share a code. The public queue seats you by rating band; a private room takes friends by code and starts when everyone has pressed Ready.
  3. Race to Accepted. The clipboard is locked and leaving the tab hides the board; three strikes disqualify. Wrong answers cost only time.
  4. Read the winning code. After the bell, the winning submission opens for both sides. A win pays 40, 60 or 90 XP by difficulty and a third of it to rating; the loser keeps 25%.

Who it is for

Anyone who solves faster with something at stake, and pairs of friends who want to race the same problem and let the judge settle it.

Frequently asked questions

How are opponents matched?
In the public queue you are seated in the first waiting duel of the same mode within ±200 rating; the band widens by 100 every ten seconds until someone fits. Private rooms use a six-character code and start once everyone has pressed Ready.
What decides the winner?
The first accepted submission on the problem or bug hunt, wherever it was made. There is no time limit, so a hard problem can take as long as it takes. If your opponent leaves and does not come back within two minutes, you can claim the win.
What about cheating?
The clipboard is locked, switching tabs or apps hides the board, and screenshot shortcuts are refused. Each attempt is a strike; being away for more than three seconds is a strike; the third strike disqualifies you and the other side wins.
What does a win pay?
In a duel from the public queue: easy 40, medium 60 or hard 90 XP to the winning side, and a third of that to rating. The losing side keeps 25% as consolation. Walking away hands the other side 50%. Private rooms pay no XP or rating — they are for playing friends, not for the ladder. Duels are unlimited on every plan.