The question came up in last night's session…
If a character has enough XP and time, is there any reason they cannot trigger the Level Up move twice in succession?
In this circumstance events have been coming fast and furious for the last day in-game, and it could be a while before the characters have a chance to get some downtime. (They're busy saving the city, and all.)
I don't see anything in the rules that would prevent it, but it does conflict with the strong prohibition on "skipping" a level that the D&D tree of games has, and from which DW intentionally draws so much of its flavor.
Best Answer
In Dungeon World, moves are triggered by narrative, period.
If a character has enough experience and can afford to spend "hours or days", then they can reflect on their experiences and hone their skills. Doing so triggers the Level Up move. If they then have enough experience and choose to spend more hours or days, then the move is triggered again.
Claiming that you can't trigger the same move twice when the narrative demands it is the same as claiming you can't trigger Hack And Slash twice in a row in combat.
Remember, DW is a narrative game. Any resemblance to D&D is superficial. If the narrative demands a training montage, then queue up Eye of the Tiger.