Question

What are the DW OU rules?

Comments

Not sure I understand your question.

---

in showdown they have a tier that is called DW OU I know dw ou means dream world ou but do all pokemon have to have their dw ability?

---

Its basically you can use any pokemon even if their dw ability is not released like contrary serperior, shadow tag chandelure, etc.

Answer 1

Here is Smogon's FAQ on DW OU. They can do a better job of explaining than I can :)

Link