Initially we followed core rules allowing resistance at top of round. But this soon fell apart when a creature had its acton in a round, then got stunned which caused it no ill effect that round and then resisted it at the top of the next and then attacked again. Players felt it unfair that a stunned creature attacked in both rounds.
Your players are correct. Stunned individuals may not attack on their next action. If their next action is the next round, then that action cannot be an attack. If a multi-round stun is indicated in round 1 (after the character has already acted) then the character is stunned for round 2 as their first round of stun. Round 3 they declare their action and roll to see if they shake off the stun or else they are stunned for their second round of stun.
We then modified the rule to now say that you resist just before your next attack / action. If fail then you are still stunned for that action. This solved the issue noted above but added to book keeping. A stun now affects your next action, not the round. But it is hard to visualise what's happening and track with 4-8 players plus bad guys.
This is correct - however I am missing where it adds additional bookkeeping.
In addition if you get stunned 2 rnds in round 1 then fail to resist in rnd 2 but then get stunned 2 more rnds in rnd 2 what are you now resisting? 3 rnds of stun or a 1 and a 2? Yikes.
Just to make it more complicated, I'll add in the post-action stun.
Rd 1
Character A wins initiative and strikes (but misses).
B then strikes A and scores a 2 round stun.
Rd 2
A declares a full parry and rolls his Stamina, but fails. He can only parry with half OB.
B strikes A again scores another 2 round stun.
Rd 3
A declares a full parry and rolls his Stamina check against the 1st strike again, and then rolls another Stamina check against the second strike. He succeeds on the first, but fails the second. He is still stunned for round 3 (and possibly round 4).
B ends his life with a full out power attack and A is now dead... No reason to continue rolling
See this thread for more info:
http://www.ironcrown.com/ICEforums/index.php?topic=13069.msg169221#msg169221