What is the name of the game mode where all heroes are random?

The Dota 2 mode where heroes are randomly assigned is called All Random.

In All Random, players do not freely choose their heroes during the usual selection process. Instead, the game randomly assigns a hero to each player. This makes the match less predictable than All Pick and can force teams to adapt to combinations they would not normally draft.

That randomness changes the strategic challenge rather than removing strategy altogether. Once the heroes are assigned, players still decide how to build them, which lanes to use, when to fight, and how to respond to the opposing lineup. A player may need to make the best of an unfamiliar hero or an unusual team composition.

The name is commonly confused with Random Draft. Random Draft limits the selection pool and lets players choose from available heroes, while All Random assigns heroes automatically. Single Draft also gives players a restricted set of choices, and All Pick is the mode associated with unrestricted hero selection.