The Twenty-four Hour Animation Contest, often abbreviated as THAC, is an annual brickfilming competition where participants create a stop-motion animation using LEGO bricks within a strict 24-hour timeframe. All aspects, including writing, recording, animating, and editing, must be completed within this single day. Primarily hosted by Bricks in Motion since 2008, after initially being held on Brickfilms.com forums, THAC is a long-running and significant event within the brickfilming community. The theme for the contest is announced at the start to ensure fair competition.