Last session in my Whitehack game a single undead black knight attacked the party. They investigated an old burial site and thanks to a random encounter roll this knight charged them on his horse. The PCs were a half-demon templar, a carnival strong-man, a dark-elf wizard, an archer, and a dual-wielding assassin.
I've often had unintelligent monsters attack a random PC each round, due to the monster not caring who they attack as long as someone is within range. The undead knight was intelligent, but didn't care about self-preservation, so it charged into the middle of the group and started swinging. In Whitehack 2, higher HD monsters get more optional attacks, and the knight had three attacks each round. Since it didn't really matter to the knight who it attacked, I rolled 1d4 for each attack (the wizard was levitating some distance away).
The PCs are level 4-5 with 12-20 hit points, and the knight could do 1d6+3 damage per hit. The +3 is a house rule based on high HD. According to the rules it should be 1d6. His three attacks were all with attack value 10, which means he had to roll 10 or less, and over the target's AC, to hit. Only a few of the attacks hit, and the ones that did only removed a small part of the PC's HP. The fight lasted for two rounds until the knight was slain.
Another wrinkle is that the PCs have picked up a magical artifact from a written module that lets them heal 3d6 HP on average two times a day per person. So after any fight that doesn't kill them they heal back to full HP.
The encounter wasn't very exciting and fell flat. As you can see there are lot of things going on: mid-level play, single monster vs multiple PCs, healing magic, and so onl, but what I need help with is how to determine who to attack. The problem with randomizing each attack is that attacks get spread out over the PCs hit points, so the players never feel really threatened. Sure, they may have bad luck and get hit two or three times and that might kill the PC, but in general it's a lot safer for the PCs than if the monster focuses on one of them at a time. The players do that; they go in for the kill on the most dangerous monster first and work their way through them. But I have a hard time knowing how to determine who the monster would attack first.
One option is to base it on a single die roll at the start of the fight. This was suggested by one of the players after the session. Say that the knight attacks the templar PC based on a 1d4 roll. It would keep attacking until the templar is incapacitated, unless something happens that makes it switch target. This switch would be determined by me based if some other PC becomes a more obvious target.
Another option is to attack the first or last PC of the group. This is usually the case in dungeons for obvious reasons, but you could also attack the first PC that enters the forbidden forest or something similar.
Another option is to decide if the monster goes for the metal-clad templar or the robe-clad wizard first, based on monster psychology.
I've been accused, only half-jokingly, by one player to always try to kill his particular PC in every game I run. Looking back it's certainly true that his PCs has died more often than others, but not based on me singling him out or him making really stupid decisions. He usually doesn't play the most obvious target, but for some reason his PCs gets killed. In one Whitehack adventure two cultists with daggers jumped out from hiding and attacked the four PCs. I rolled 1d4 for each cultist, and they both attacked this player's PC. Next round the cultist still standing made another random attack, hit the same PC and killed him. Four level 4 PCs met two 1 HD monsters with daggers, and he was killed.
Bad luck, sure, but if I do some self-analysis I think this random-attack stuff is in part because I don't want to be the jerk GM that use my power to single out players and put their PCs out of play. Randomizing targets takes the decision out of my hands, especially since we do open rolls. Making an initial random roll and keep hitting the same PC is a nice middle ground, but I'd like to hear other suggestions on how you determine who is attacked.
The main situation described above is a single monster, possibly with multiple attacks, that attacks four PCs. But if there are four monsters and four PCs, I think the players would focus their attacks while I would have the four monsters attack one PC each. This is more based on giving each player something to do, rather than the most tactically sound thing for the monsters. They would probably be better off if they all attacked the most dangerous-looking PC first. This would lead to the templar being attack by all monsters in every fight, and I'm not sure that would be very exciting for the group of players or that specific player.
Any thoughts on how to handle this?