A Neverwinter Nights Persistent World -- Register using the -forum_pwd command in-game.
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It seems that if someone is in sneak when passing a lycanthrope it will not trigger the will check at all; even if they can see them. As long as the name is grey there's no attack. This feels like a bug.
The will check has nothing to do whether there's people around them or not. You can pretty much berserk against the air. Rage against the storm.
Just out of curiosity, how close were you stealthing?
A fix for this has been pushed.
Please keep us apprised of how it develops.