Not sure if this has been reported before but I wouldn't be surprised.
Anyways, two bugs:
1) If you're in a safe spot attacking a monster, the npc being 1-3 squares apart from you, and you decide to move one square, towards the npc, or left or right of the npc, the npcl hit you (only once) even if it's still supposed to be out of range.
2) The someone else is fighting that bug. If there are 2 or more players around and I attack an npc first, the other players still have the opportunity to hit the npc, regardless of the "someone else is fighting that" timer.
If I hit it first and move to a safe spot before the "someone else is fighting that" timer is supposed to be over, the players that attacked the npc after me apparently have priority over me if they click "attack" again. It gives me the "someone else is fighting that" message instead and I'm unable to attack the npc.
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Apologies if it's a bit confusing but I can make a video sometime if that's what whoever's reading this would prefer.