I'm taking a break from Grand Adventure to work on some other game design, and try out Powered by the Apocalypse. I'm taking an idea from awhile back, called "Fairy Soul", and giving it specific mechanics.
First, let's put something on the table: a sample opponent for PCs in a typical Fairy Soul game.
These are half-awake fairies who have possessed their human jails and now dominate them. They follow the templates laid out by the archetypes of the universal unconscious: vampires, werewolves, and other bogeymen.
Conditions: pick any two of Violent, Aggressive, Seductive, Cunning, Enigmatic, Hideous, Weird
What have I learned about PbtA by writing something like this?
In traditional RPGs like Dungeons and Dragons, a monster like this would have a set list of effects it could do, how often it could do them, what each one did, and so on. Damage would be clear and quantified. There was a chain of events that started with "it's the monster's action" using the initiative rules, and most steps in that chain plugged from one rule into the next. Initiative goes to GM's decision about action. The GM's decision goes into an attack roll (for an attack) or a declaration followed by a saving throw (for many spells). An attack plugs into the attack bonus, the dice rolling system, the PC's various defensive rules, and finally hit points and damage.
In this monster's case, the GM can just say what the creature does. The major options come from the move list.
For example, I can say "suddenly a second vampire appears, and it's your young friend from earlier. This vampire has drained her blood and raised her as one of its own kind. What do you do?" That action is in keeping with the "spin bloodstained fairy tales…" move. I didn't roll to hit the young friend from earlier, there was no resistance roll, it's just a part of the story.
The thread of action wove its way from the GM ("I need something to do now") to the move list, and back to the GM. Further actions will come from player declarations, backed by player move mechanics. Those moves will generate further fiction, and so on. There's no long chain of rules that feed into each other. The players are incorporated as vital components into the process of rules resolution.
I'm actually pretty proud of some of the phrasing here. "Spin bloodstained fairy tales from the threads of human lives" hopefully tells you something very specific about what this thing does, even if it's vague on the details of how.
"Struggle for control against my human host" is both a move the creature makes, and an opportunity the players have for defeating it. Like a Fate aspect, it's doing double duty as strength and weakness. I didn't define any particular mechanics for exploiting it, like "roll +Heart, on 10+ you overcome the renegade fairy soul and recover the human spirit within". I mean, I could, but why?
Poetry is efficient. It suggests and implies, rather than stating. It overloads itself with meaning. Good opponent moves will do the same thing.
How do you defeat one of these mythological monsters I've statted. It doesn't have hit points!
I've got this "conditions" mechanic, which I'm still playing around with. The idea is that maybe you can do stuff to trigger all the conditions on the monster, and then it runs out of stuff to do itself and you can kill it then. But even that isn't necessary.
Fairy Soul isn't the sort of game where you whittle down an opponent hit point by hit point. In the fiction that inspired it, people can be placed in peril, but nobody is seriously hurt. So tracking injury is simply not a useful thing. Either you're doing well, or you're doing badly, or you're victorious, or you're defeated, and it's never simply a matter of making one more successful attack.
So how do you beat one of these monsters? Two of their moves suggest options.
"Wear the mantle of a creature of legend" means that the traditional remedies ought to work. A blessed bullet will kill a werewolf (since silver is a later invention). Holy symbols can ward off a vampire. Fire probably burns mummies.
Okay, maybe a monster has erupted from a friend of the PCs and they want another option. "Struggle for control against my human host" gives the players a chance to bring someone back from this fate.
"Fine, fine," I hear people saying. "Just tell me how to kill it." And the answer is: "tell me a story where you are able to kill it, and along the way we'll sometimes throw dice to add inflection points." But I haven't told anyone "here's how to kill a monster". At most, I've established that in this game, beating opponents is mostly handled through storytelling. I don't need a mechanic for hit points, so I don't have one.
Instead, the mechanics I have written, such as moves, reinforce and structure the story. When you see a move, your inclination is to use it. It sets expectations.
I gotta say, PbtA is a pain in the ass if you are hoping for a generic system where the group sits down and bangs out a setting. I know gamers who say "well good! the game should say something". And sometimes, I think that's true. I love games that show me a specific vision of a world, and invite me to participate in it.
That said… some settings don't emerge fully formed from a single person. They come from mutual interaction, suggestions bounced off of each other, and synergies between fun-loving gamers. In Fate, I can be up and running in half an hour, because there's standard rubrics for everything that I can plug into.
Playbooks vs. Fate characters might be another sticking point. I don't know any Fate players who would be all like "yeah, Mr. GM, please write all my stunts for me". While playbooks do offer some flexibility and customization, it's not the blank canvas that Fate offers for painting a unique character.
In short, it's free verse, rather than Fate's metered rhyming poetry. There aren't many meta-rules that teach you how to make rules of your own.
PbtA feels like a system for when you have something specific to say, and it's more important to sell the players on your vision than for you to accommodate theirs.
For Fairy Soul, which exists in a specific time and place
and has a specific message, PbtA feels like a good
fit. But it's a lot of