How To Summon a Demon: A Fate Core Mini-Hack

For the last couple of months I’ve been running a Fate Core RPG set in the Buffy the Vampire Slayer universe. A sequel to a campaign I ran last year, the game chronicles the exploits of a young Rupert Giles, who has forsaken his calling as a demon hunter and retired to 1970s London. Those familiar with the tv show will remember this as a particularly dark time in Giles’ life, and we’re having fun leading him astray with the temptations of dark magic.

Related to that, one of the players has taken an interest in demon summoning, and especially as a way to make her character more effectual in combat. This prompted the question of how to represent such a thing in Fate Core. The ideas I’ve presented below are my first draft, and I’d be very interested in hearing people’s perspective, and seeing how others have approached this challenge.

For context, my design goals are as follows:

  • This is something for SOME characters to invest in with stunts, not a new option for all characters, so balancing the ability against other mundane skill-sets is key.
  • Unbound demons, in the form of player-summoned NPCs that are as likely to react with hostility as assistance, have already featured in the campaign. For characters investing stunts into this ability, I want something a little more reliable.
  • I don’t want anything that requires players to track multiple stress tracks on multiple character sheets, or anything else that results in a lot of extra book-keeping.
  • I also don’t want anything that allows some players to get twice as many goes as anyone else in a conflict. For this reason, I’m probably not interested in the “bonus pets” style of demon summoning – I actually think that the create an advantage action works fine for this anyway (“roll Rituals to create Demon Familiar as a situation aspect that can be invoked the next time she helps you out”).
  • The player I’m creating this for has indicated she’s happy for this to replace her normal combat actions, which suggests that a “puppet master” approach to controlling summoned demons is likely the way to go.

And this is what I’ve got so far…


  • To summon a bound demon, roll to overcome with the Rituals skill[1]. Difficulty is +1 usually, but increases by 1 if summoning on a time limit (e.g. you need it this turn), and by a further 1 if you are in combat. If you succeed, the demon arrives in your zone.
  • Write your demon’s high concept aspect, which describes the kind of demon it is. In addition, give it the trouble aspect “Summoned Creature” to reflect that it requires the concentrated will of the summoner to remain animated (this can be compelled when the caster is under stress to forcibly end the spell).
  • You get a certain amount of skill points to determine what the demon is good at – by default, 10. A skill at +4 costs 4 points, a skill at +3 costs 3 points etc. Arrange this into a skill pyramid, making sure that no line is wider than the one below it as normal.
  • Bound demons don’t get stunts normally, but you can spend a fate point immediately after the summoning to give it one.
  • Bound demons don’t have stress boxes or consequences.


  • Whilst a summoned demon is in play, it takes all of the caster’s will to control it. You cannot use any of the caster’s skills for as long as the binding continues – you can only use the demon’s skills. The caster’s skills are used only to determine your demon’s initiative order in conflicts. The demon acts whenever your character normally would, instead of using the demon’s Notice or Empathy.
  • Your demon moves and takes action the same as any other character. To all intents and purposes, it is your new character sheet. The only exception is if your demon is attacked – it defends as normal, using its own skills, but any shifts of stress inflicted are applied as mental stress against the caster.
  • The caster remains motionless in their zone for as long as the spell continues. You can take no actions. Any incoming attacks roll against a passive defence of +0.


  • You may choose to end the spell and return to your caster’s body at any time. This will usually happen because you want your caster to move, or take an action with their own skills.
  • If the spell ends under unstressful circumstances, there is no further impact. However, if the spell ends under sudden or stressful circumstances (e.g. you suddenly need to make a defend roll against someone attacking your body, or took a compel on “Summoned Creature”), create a situation aspect to reflect your body-shock.
  • Either way, when your will is no longer exerted over a bound demon, it is immediately destroyed. If you want to return to your demon body, you need to roll to summon it again.

Summoner: You can summon bound demons using the rules stated above. You have 10 skill points to build your demon with.
Deeper Summons (requires Summoner): Increase the number of skill points you get to create a summoned demon by 5. This stunt can be taken multiple times.
Unleashed (requires Summoner): When you end the spell to control a bound demon, you can choose keep the demon in play rather than allow it to be destroyed. It then becomes an NPC, unbound and uncontrollable, as dangerous to the caster as it is to all other nearby characters. Give the demon stress boxes based on its Physique/Will, and use its Notice/Empathy to determine its new slot in the initiative order.

Feedback is welcome! I think I’m ready to start using this in our campaign and see how things go, but any tweaks for balance or clarity before it goes to the first playtest would still be very helpful.

[1] In our campaign, we have four new skills that characters use to cast magic: Occult (for knowledge), Spells (for white magic/defending), Hex (for black magic/attacking) and Rituals (for pretty much anything, though it’s usually time consuming and has bizarre prerequisites). Every Fate Core game has its own special way of handling magic, so I expect GM’s using this ruleset to adapt it to their own magic system as they feel appropriate. If just using the Fate Core default skill list, demons could be plausibly summoned using the Crafts, Lore or Will skill.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s