In "Team Fortress 2", the "Bill's Hat" is a reference to the game "Dota 2".

The statement is false because the Bill's Hat in Team Fortress 2 is not a direct reference to the game Dota 2. The Bill's Hat is actually a promotional cosmetic item that was originally a hat worn by the character Bill from the game Left 4 Dead. It was made available in Team Fortress 2 as a cross-promotional item through a ticket system during a limited-time event. Therefore, its origins are related to Left 4 Dead and not Dota 2.