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Compete in a contest

Contests are open invitation for wardens of all skill levels.

Code Contests

C4 code contests leverage a community of security researchers and smart contract experts to provide cost effective and rigorous code reviews in a gamified manner. We aim to create a way for both beginners and exceptional white hats to showcase their skills while making DeFi platforms more secure.

Stay up to date with new contests by following C4 on Twitter.

There are three actors in Code 423n4:

Wardens hunt for bugs in the smart contracts of decentralized protocols.

To participate in a code contest as a C4 Warden, join the C4 Discord to register or join a team.

Sponsors create bounty pools to attract wardens to their contests.

Judges are responsible for allocating bounty pools to wardens based on their performance.

To participate in C4 as a Judge, please contact a C4 Organizer in the Discord.


The scoring system has two primary goals: rewarding contestants for finding unique bugs and making the contest resistant to sybil attacks. A secondary goal of the scoring system is to incentivize contestants to form squads and encourage coordination.

Bugs are divided into three risk categories:

  • Low
  • Medium
  • High

For more details regarding scoring, please refer to the judging criteria.


Wardens are awarded shares for bugs discovered and those shares give the owner a pro rata piece of the pot.

Low Risk Bounty Shares
1 * (0.9 ^ discovery count) / discovery count

Medium Risk Bounty Shares
3 * (0.9 ^ discovery count) / discovery count

High Risk Bounty Shares
10 * (0.9 ^ discovery count) / discovery count

At the end of the contest, each bounty share is redeemable for:
Bounty Pot / number of Bounty Shares.

Duplicate Submissions
Should the same bug be submitted by multiple Wardens, Judges have the discretion to place these bugs into the same bucket, in which case, the award will be shared among those who submitted.