Tales and Chronicles
Jewel of the North, formerly know as vincegetorix
I did think of it in terms of 13th Age escalation choice, and a little bit like momentum from Ironsworn.
I like it a lot. The Escalation die of 13th age is a cool mechanic. Would the Momentum die be added to all creatures, players and foes or just the players?
I would probably add a few little bonus to the Momentum that everyone can benefit:
Like:
Momentum 2: Drinking a potion now requires a Bonus Action
Momentum 4: +5 speed, +1 item interaction per turn.
Momentum 6: +1 Reaction per turn.