Player can prematurely challenge a boss or such that they don't have some mandatory item, skill, or such to defeat them, guaranteeing defeat in the ensuing battle.
Alternate name: Early challenge
The first video game about Premature challenge was released on April 24, 2012.
* Player can challenge the boss before the plot thinks this is OK, causing the boss to steamroll over the player character regardless what they do.
* An item, skill, spell, or such is required to defeat the boss but the game allows to challenge the boss before the player character has this thing (skipping the fetch mandatory thing and trying anyway; may not be obviously needed). Very easily happens if the game is non-linear.
* RPG or similar where player can challenge a level 99 boss when they're still at level 1. Especially with static level advancement.
... and some other things that are comparable to the above.