Which scenario requires a playoff match to be replayed?

The scenario that requires a playoff match to be replayed is when an arena fault leaves a robot inoperable. In the context of robotics competitions, an arena fault refers to a failure or malfunction of the competition field or system components that impacts the operation of a robot. If a robot cannot function due to such an external fault, it creates an unfair disadvantage for that team. To ensure fairness and integrity in the competition, the match is replayed so that all teams can compete under the same conditions without being affected by issues outside of their control.

In contrast, a tie score would typically lead to predetermined tiebreaker rules being applied rather than a replay. If the same conditions apply, it suggests that the circumstances haven't changed to warrant a replay. Lastly, the participation of a different robot would not necessarily qualify for a replay, as the match is expected to be held with the same competitors as initially scheduled. The focus is on fairness and giving all teams a chance to compete under optimal conditions, which is why an arena fault is the primary reason for a match to be replayed.