The player (PC) or the GM (for creatures) who triggered the lasting effect is responsible for tracking and reapplying it each round. This means that the player or the GM must remember to reapply the effect to the target at the beginning of each round.
More precisely:
- The PC must remember the positive effects they benefit from and the negative effects they have applied to their opponents.
- The GM must remember the positive effects that benefit their creatures and the negative effects they have applied to the PCs.
If the PC or the GM forgets to reapply the effect on a given round, that round is simply lost, and the duration of the effect continues to decrease normally.