Now that I've got the new way potencies work, in a general sense, I can return to NPC spceial abilities. I still don't want resources to manage on the NPC side. We've seen how well that worked. However, creating interesting opposition requires something that can do more than deal damage. No, this game isn't super-meaty in terms of combat, but still, you do want to mix up the violence now and again. Descriptions are great, and I intend to use them quite a bit, but since a player experiences a game in large part through how it affects his character sheet, I want to put in a few special abilities, similar to potencies, that NPCs can use to make them stand out as different from one another.
In the interest of keeping all the calculations on the player's side, however, I'm staying away from the idea of activating them on my own somehow though. I'm not sure if I'll keep the encounter pool, or how it'll work if I do, but I do know that's not going to be the way that I'm going to invoke their abilities.
So how to do it? The same way we're trying to do everything else in this game: margin of success/failure on the player's roll. Since an NPC's stats are the target numbers for attack and defense rolls made by the players, the special abiltiies can things that trigger when certain margins are hit.
For example, a brilliant swordsman NPC might have a riposte abilitiy that kicks off with a margin of 3. He has a defense of 5. A player takes a swing at him, but only comes up with 2 successes for the roll. That triggers the swordsman's riposte ability, which means he gets an automatic, free attack against the player. This happens whenever anyone misses him by 3.
Like potencies, these can be tiered as well, with greater effects triggered by greater margins. And there's nothing that says a player has to utterly fail in order for a special condition to kick off.
For example, a cultist has a special ability that allows him to call for aid from others in the crowd when he's in trouble. When a PC makes a successful attack with a margin of 3 or less, the cultist successfully calls another member to his side to stand against the PC.
Now, I thought Gifts as NPC stats was a good idea too, so this sounds nice in theory, but the only way to be sure is to test it. I'd like to say I'm confident, but the last idea worked out so poorly I'm instead going to say I'm cautiously optimistic.