The chat filter is used to prevent bad words from being said in chat. Words detected by the filter are blocked and the player may be automatically temporarily muted, preventing them from speaking entirely. If this happens, a report is sent to RocketSnail, who can then investigate and ban the player if necessary.
The software used for the filter is Community Sift, which was created by RocketSnail's brother.
During the Experiments, players found ways of bypassing the filter, so RocketSnail has had to adjust the filter and increase the threat level several times.