How do i coop with a friend ?
 

Hi me and my friend jsut patched and returned to the game, but we cant seem to play together, i added him to friends list but thats it...

bumping up

You can siege together all the major NPC cities in the game and also play together some quests. Get your armies with similar strengths close to the same city or quest, then one of you got to siege the city or enter the quest and select coop. You can also write the name of your friend to the field in there. Then, your friend has to accept your coop request and you shold be ready to go!

we have been trying to test out this feature and more detailed info on it would be very helpful. For instance:
Can different races work together?
Do the army's absolutely have to be similar strength, if so how similar?
Do both players have to be on the same quest or can a more experienced player help a less experienced player?

Yes, different races can work together - you can be an Elf and invite an Orc player to help on a quest/siege.

Hmm, not sure about the exact strength requirement, it might be something like +/-50%. Edit: Just looked it up, it's +/-70%

Only the player requesting co-op has to be on the quest, the other player could have completed that quest months ago, not be at that quest yet or not even have the option to do that quest (e.g. different race).