What it does
Any move in the self-destruct category — Explosion, Self-Destruct, Misty Explosion — simply fails if Damp is active on the field. The Aftermath ability's post-KO chip (dealing 1/4 HP to the attacker on contact) is also blocked. Damp applies to both sides of the field, including the holder itself — the holder can't use Explosion either, which rarely matters but is worth knowing.
Who runs it
Politoed (0%) is the primary drizzle setter in rain teams. When players use it, they're picking Drizzle, not Damp — Damp is the backup slot that essentially never gets chosen. Its Champions usage is 0%, reflecting that rain teams exist but build around the weather effect, not Explosion prevention.
Bellibolt (0%) also sits at 0% usage. Both carriers tell the same story: in the current Champions format, no one is selecting these Pokémon specifically for their Damp slot.
How to use it
Damp is a completely situational ability. In a format where no popular Pokémon uses Explosion, it provides no benefit. The current Champions meta has very few Explosion threats, which means Damp goes from 'reactive insurance' to 'irrelevant' almost every game.
The one scenario where Damp becomes genuinely useful: doubles, where Explosion can one-shot both of your Pokémon simultaneously. If your opponent's team preview shows a Pokémon that commonly runs Explosion, landing a Damp holder on the field can negate an entire win condition.
Tips & strategy
In formats outside Champions — unrestricted play, Battle Tower, specific Reg sets with heavy Pokémon like Snorlax or Regigigas — Damp's value climbs considerably. Self-destruct moves do exist and get used when they're meta-relevant.
The 0% usage across both carriers in Champions is honest data: neither Politoed nor Bellibolt is being used for this ability right now. That's not a judgment on the ability itself — it's the meta giving it nothing to do.