A stage hazard is any aspect of a stage (that is, a stage element) which could pose a threat to players. Most stage hazards deal damage and knockback, while the remainder include a wide range of effects, such as sudden movements of the stage or a panning camera that can carry less agile characters into the blast line. A stage hazard should not be mistaken for any element which might aid or save the opponent, such as the Support Ghost in Yoshi's Island, although the same element may play several roles.
How predictable a stage hazard is and how much influence it has over the match are factors usually considered when deciding stage legality. Stages with many or overwhelming hazards are typically banned in tournaments, as they tend to interfere with the outcomes of matches or because the competitors only value aspects of a match that they have control over without overcentralizing the match.
Some stage hazards may be extremely minute or subtle, or only apply to certain characters. For example, the balloon in Smashville may unexpectedly collide with Ness's PK Thunder, making him temporarily vulnerable or leaving him in the helpless state if he is in the air.
Stage hazards often play a role in improvised combos.
In Super Smash Bros. Ultimate, stage hazards can be turned off.
Types of stage hazards
Stage hazard switch
In Super Smash Bros. Ultimate, stage hazards can be turned on or off. Its description in-game says that it turns off hazards "like environmental changes and enemies"; however, the way it is implemented from stage to stage can vary—for example, some stages (such as Saffron City) have moving platforms kept still, while others (such as the rightmost platform in Frigate Orpheon) may still move. The list of stages that have changes follows:
Additionally, several roaming or transforming stages stay locked in a certain stop in certain spirit battles.