It can't escape and it can't attack!
Actually, they fixed this in generation IV. Any pokemon with the ability shadow tag can escape if the other pokemon also has the ability. So Wobuffet can switch out against another.
How to change your username
How to add a user avatar
Why was my post hidden?
Flags vs Downvotes
Official PokemonDb League
Type a Pokemon name, type, move or ability to see instant results.