I often talk about equal distribution in gaming, although normally I’m referring to time, loot and opportunities for awesome – all positive things that should be shared evenly.
What about when it comes to who the two-ton behemoth wielding a dented Buick is targeting?
Having enough bad guys for everyone is a good start – everybody gets a goblin or two and then there’s no having to decide, at least initially. But there are often “elite” baddies to make a fight interesting (the ogre leading the goblin horde, for instance), and who they target stands out a bit more. Naturally, you don’t want an ogre for everybody since you’d likely kill the party – so who does it go after? The first PC it sees? The last one who hit it? Does it ever changed targets or just zero in on one character until they’re flattened into pavement and then move on to the next?
Naturally, in most game systems, different builds handle being targeted differently. For instance, in Pathfinder, you want the rogue dodging the wizard’s evocations, you want the fighter or paladin dead center against the two-handed Buick-wielder, and the cleric is a good fit for the ghasts with their grabby disease hands. But are the NPCs going to target the PCs who are best at defending against them, or should the two-handed Buick-weilder golf the cleric while the wizard electrifies the fighter instead? As a GM, you know what defenses your players have and where the optimal match-ups are in both directions, so you can’t easily make an unbiased decision (humans, it turns out, are terrible at being random), so how do you design encounters so that they don’t prove lopsided or focus too heavily on one PC over another?
MMOs have taunt mechanics that justify bad guys targeting the person best poised to take the damage while all the glass cannons rain hell from a safe distance, but ‘taunt’ barely makes sense as an in-character happening in the best of circumstances (raging bulls and angry humanoids with fragile egos) and zero sense in others (undead, machines, clever foes, etc.). That said, some systems do have mechanics for exactly this, whether it’s intimidation, distraction, or some other form of interception that PCs can trigger to make a decision on behalf of the NPC as to who to go after next.
But barring that, it’s entirely on the GM to decide, and your choice can drastically change the way a fight will play out, from the boring to the unwinnable, with each player’s experience potentially being different from those they’re sitting next to.
Naturally, one option is to have your damage dealers shift targets at each opportunity to spread things out as evenly as possible – your enemy wizard uses weaker AoEs or rotates targets as they go, rather than trying to burn on PC to the ground (and likely succeeding). It’s not a “realistic” choice for a competent fighter who would numerically benefit from having one less sword swinging at their face, but from a game perspective, it imperils all the PCs without truly risking killing any of them for the most part.
The chief problem with the even split method is that it often means a somewhat boring fight and an “elite” baddie who doesn’t feel very scary in the end, or very smart. The fight starts to seem less personal than a focus-fire approach, where a given PC gets to feel singled out and may get to enact a particularly satisfying vengeance while the party deals with the rest of the encounter.
If you opt for the focus fire approach, there’s where I recommend having your NPC pick out the PC who has the best defenses against them (assuming they’re “defenses” and not “immunities.”) Have your wizard sling enchantments and necromancy at the cleric all day while the PC works their way up to the ledge the wizard is on to give them the old +1 mace how-do-you-do. Meanwhile the rest of the party clears the goblin trash. Just remember that the next fight, it’s someone else’s turn, and that not every PC is built to have the spotlight in a combat scenario. Some will get their moment in social combat or the like, and the focus-fire approach makes a good counterpart to combat-focused players who poo-poo social encounters to remind them of the time they went toe-to-toe with a cave troll while the bard just strummed along.
You can also deliberately have NPCs target the PCs who are weakest against them to amp up the difficulty of an encounter that seems like it’s going too quickly or too easily for the players to enjoy it. The opposite is also true – if your Buick-wielding ogre gets in a lucky shot and golfs the rogue, have him switch to the barbarian or fighter next while the cleric has time to get to the rogue and get them back on their feet, just in time for them to get their revenge in a future round.
If you want to prevent the fight from feeling too much like a fix (making the safety net invisible, as it were), have ready in-character reasons for shifting tactics. A clever foe can also be arrogant, and after a lightning bolt nearly fries the party cleric, they might write the PC off and move on to the next, muttering something belittling as they go before conveniently turning their back on the still-smoking PC. A round or two gives PCs and NPCs alike a better idea of what the other can do, making it sensible that smart baddies would adjust to more optimal match-ups as the fight goes on – they just needed a few rounds to figure out what those were.
Feral or raging opponents can be pointed any way you like them – first person they saw, last person who hit them, largest opponent, smallest opponent, anything that makes a given PC into an outlier. Have a few on hand if players start to feel cheated when an NPC doesn’t finish off a weakened PC or when they shift up targets suddenly so that it feels real while at the same time getting the encounter to the sweet spot it needs to be in for everyone to be having fun.
And then, well, I believe Zapp said it best.