Which deduction corresponds to a gymnast falling off the beam during a routine?

When a gymnast falls off the beam during a routine, the standard deduction is 0.50. This deduction is applied because a fall disrupts the performance and significantly affects the score based on the gymnast's overall execution and stability on the apparatus. The rules of gymnastics scoring are designed to penalize such major errors to ensure that the final scores reflect both the difficulty of the routine and the skill with which it is performed. In the case of a fall, a 0.50 deduction is appropriate as it captures the severity of the error without being excessive, allowing for a fair assessment of the routine overall.