Fouls (3.C): It is the responsibility of all players to avoid contact in every way possible.
Avoid contact in every way reasonably possible, while still playing ultimate. Some contact is inevitable, but players have an affirmative obligation to make reasonable efforts to avoid contact.
Dangerous Play. Actions demonstrating reckless disregard for the safety of or posing a significant risk of injury to fellow players, or other dangerously aggressive behavior are considered "dangerous play" and are treated as a foul. The proper call in such circumstances is "dangerous play" and play stops. This rule is not superseded by any other rule.
The following are non-exhaustive examples of dangerous play:
Dangerous play is considered a foul regardless of whether or when the disc arrives or contact occurs.
The vast majority of dangerous play will involve contact between players. However, contact is not required for a player to invoke this rule where there is reasonable certainty that contact would have occurred had the player not taken steps to avoid contact.
A player is not required to hold their position and receive contact in order to call "dangerous play," but the mere possibility of contact is insufficient to justify a call. Furthermore, if the offending player stops or changes their path such that contact would not have occurred, contact was not "reasonably certain."