Custom Moves: Now I am your Master
The basic mechanic of Dungeon World (currently on Kickstarter) is so simple: roll 2d6, add your attribute modifier; on a 10+ you hit it hard, on a 7-9 you get a partial hit or complications, on a 6- bad stuff happens. As a DM, it makes it very easy for me to come up with custom ruling on the fly by creating moves for the current situation.
In one of our recent sessions, Ysolde the Wizard agreed to become the apprentice of Hi Xaphon, a wizard the party ran afould of a couple of sessions ago. Ysolde's player, Phil, and I chatted for a bit about what being an apprentice means. Then Phil took a bathroom break. As the other players were still planning their upcoming Goblin raid, I quickly jotted down a custom move:
When you exchange blood and power with your new master and bind as their apprentice, roll 2d6 plus your Wisdom modifier:
10+ hold 3 7-9 hold 1
You can spend your hold, 1 for 1 at any time for one of the following:
Privacy your master can't scry you, doesn't know what your up to, or sees your preferred version of events.
Help appeal to your master for aid through your magical bond and they will help you in some way appropriate to the situation and their powers
Turnabout turn your apprenticeship bond against your master in some way
Ysolde rolled a 9 or so, gaining one precious hold on her master.
It's funny how moves snowball, though. Later in the same adventure, Terek, the Paladin, laid hands on Ysolde to heal her numerous wounds. On a 7-9 with Lay on Hands, the Paladin takes the subjects wounds onto himself. I briefly described Ysolde's wounds and asked which one Terek wanted to take. "Oh, I'll take that small cut on the arm, since I'm only healing one HP". Of course that was the cut Ysolde received on the apprenticeship bonding. So now our Paladin has some kind of psychic connection with Ysolde's arcane master...