Are opportunity attacks different for monsters?

[Ganadai]

I noticed that monsters do not have "basic attacks". Does that mean you use there at-will attacks as basic attacks?

PC's don't get to use their at-will attacks for OA's.

[EDIT]

Never mind, just figured out only the attacks with a circle are basic attacks. Still kind of strange that some monsters basic attacks do ongoing damage and/or impose conditions upon PC's, but PC's basic attacks suck.

[/EDIT]

 

[Drakhar]

*coughheavybladeopportunitycough*

As to your question, the only monsters I've seen that don't have a 'basic' attack with a weapon, are those who have no weapons and instead slam into you (Zombies, oozes, etc) The monster powers do however have handy little symbols to tell you which ones are their basic attacks for OA's.

 

[kouk]

Fighter's OA basic is pretty darn good; it stops enemy movement