I did a forum dive, but didn't really find anything on this. I'm trying to do an NWoD+fanelines-> GURPS conversion, and most of it is pretty straight forward. The only thing giving me trouble is the core power of Changelings: the ability to make magicaly-enforced oaths and contracts in play. (Geniuses are a little tricky, but modular abilities and gadgeter(aspected) should be enough)

What does the hivemind reccomend for creating magicaly-enforced oaths in play?

Quick question. Are you talking about control/battle design? Or plot?

These are two different things.

You make a pledge to "never retreat from danger" not only is running now disabled, but controls can be tweaked so that you cannot go back a screen (the otherwise teleport event reminds you of your pledge), but walking is such that if you are facing left, you cannot go right, if you are facing up, you cannot go down. You have to turn a few times to go in the opposite direction.

Likewise, a magical oath of poverty prevents you from getting money/spending money in town. You have to harvest items to heal.

A plot-based oath is rather easy to do, but adds little to the game, as characters don't follow it when outside cutscenes.