Extension to the above -- Not Beta ready. I've got over 500+ Killcount at raids on OSRS and these are the problems i bumped into in 1 single raid I did.
Small muttadile, only one person can attack it should be multiple.
Vanguards - When standing in corners of the room all of them are able to attack you, this will be a problem when soloing.
Also, when i left vanguards to trade another player for supplies, we went back in the room and all of the vanguards were nulled.
Tekton - Killed him, wasn't able to pick up the supplies it dropped.
Multiple map glitches.
Shamans - Was in a 2 man raid, There was atleast 8 Shamans. On Osrs the amount of shamans scale to the number of people in the raid.
Also after defeating the Shaman room when we tried to exit to the next room we were stuck in a loop consistently leading us to the shaman room.
Vasa - Only one of us was able to attack the crystal which should be multi, also it appeared that vasa didn't gain health when on the crystal. Another thing Vasa never goes back to the same crystal to heal, it's always a different crystal.
Wasn't able to make potions to finish the raid.
When leaving the raid I still had Supplies in my invent from the raid Aka Xeric's aids and seeds.
Also in OSRS, The health pool of mobs/bosses scale to the amount of people in the raid.
As far as the amount you should scale the health I do not know exactly how much it should be scaled by.
