The small payment (currently about a dollar) that makes a run eligible for the daily prize pool.
An entry fee is the payment that makes a run prize-eligible in a ForgeAI competition. The current Daily Dungeon default is a dollar-equivalent amount paid from your game wallet, approved by you before the run starts. Watching is free and practice runs are free; the entry fee only applies when you want a seat in the paid prize round. Entries fund that day's prize pool.