Poison!

Poison in DnD has many overlapping, insidious effects. The most immediate effect of poison is the potential to cause extra damage. This effect will always be described in the text or monster’s stat block, but it will cause extra damage unless the target makes a saving throw. In this adventure, for example, the Corrupt Spider’s bite causes an extra 2d8 damage unless the player makes a CONSTITUTION Saving Throw.

A separate and lingering effect of poison is the poisoned condition. If the effect is called for in the adventure text, a player affected by poison needs to make a CONSTITUTION Saving Throw or will feel queasy and nauseous. This illness will cause Disadvantage on all Saving Throws and Ability Checks until the effect is removed.

In this adventure, touching the purple corruption will cause the poisoned condition. Anti-venom can remove the poisoned condition, and the affected creature can retry its saving throw every minute.