If all other party members are in town, in another zone, or dead during an event OR boss battle (one that awards a "cooperative achievement"), will the event/boss battle still award the coop achievement for the whole party?
For example, the other party member in a two-person party stays in town during [an event]—does he still get the achievement, and do both get the cooperative achievement even though the other party member wasn't present? Or everyone declines a boss battle while one person finishes it—do all party members get the achievement AND the coop achievement?
Best Answer
In my experience, both members have to be with each other to receive the achievement when it involves killing something or exploring, etc.
Example: When I was playing Co-op with a friend, he killed his first rare monster which triggered an achievement and I was back in town - clearing my inventory and repairing. I did not get this achievement (I had to earn this at a different time).
Although, if the achievement is quest related - all members of the party complete the quest at the same time which [I would think] should trigger that specific achievement.