Entry hazard
Entry hazard is a field effect on one side that damages or affects each Pokémon that switches in
Gold and Silver added Spikes. Diamond and Pearl added Stealth Rock, which deals one eighth of maximum HP scaled by Rock effectiveness, so a Pokémon weak twice to Rock loses half its HP. X and Y added Sticky Web, which lowers Speed by one stage.
Main-series games; introduced in Generation II, Gold and Silver.
4 later changes
- Ruby and Sapphire let Spikes stack to three layers.
- Diamond and Pearl added Stealth Rock and Toxic Spikes.
- X and Y added Sticky Web.
- Sword and Shield added Heavy-Duty Boots, which block hazard effects on the holder.