I'm DMing a D&D 5e campaign that has pockets of "weird time" (areas where time runs faster or slower than normal). It seems like I shouldn't pass up the opportunity to have an area where time is running backward, but I'm not sure how to do it.
The challenge the PCs will be trying to complete within the backward-running "time pocket" is to collect a certain type of mushroom that grows around a certain tree. Hidden among the desired mushrooms will be malevolent Violet Fungus, and there will also be someone hiding outside the time pocket who is trying to sabotage them (perhaps just shooting crossbows at them).
My initial thought was that:
- upon entering the time pocket, they will find that they have already collected the desired mushrooms, but also have suffered necrotic damage from the violet fungus and a few have taken crossbow bolts.
- If they leave the time pocket without doing anything, the damage will be undone and they will no longer have the desired mushrooms;
in order to keep them, they will have to complete the causality--essentially, put the mushrooms back (and to avoid taking the damage, they will have to avoid the sources of that damage).
Does that make sense? Am I missing any gaping plot holes that this would create?
If anyone has tried this before, what worked?