Broken

A broken gameplay element (whether it be a character, stage, item, situation, etc.) is so overpowering that it ruins gameplay by supplanting other gameplay elements. A classic example is Fox in Hyrule Temple; he can outrun almost every other character on this massive stage, and can chip the enemy's health by firing lasers; thus, he can easily win matches by percentage difference. This type of unfair strategy is broken and action is taken (in this example, banning Temple from tournament legal stages) to prevent it from impacting competitive play.