A Playbook Idea: the Doppelgänger

A Playbook Idea: the Doppelgänger

A Playbook Idea: the Doppelgänger 

I was rereading some old D&D modules this week, the A1–4 Slave Lord series, looking for some Dungeon World inspiration. A1 has at least two instances of doppelgangers almost casually inserted into some room encounters, with mention of their Instinct being (of course) to replace PCs. 

In thinking about how to pull that off in a DW game, it occurred to me: why not a doppelganger playbook? If/ when the doppelganger gets his chance to replace a PC, slip the player the different playbook, complete with its own moves, and maybe a few goals/ objectives to replace Alignment and/ or Bonds. The player completes a goal, mark experience. 

Thoughts? Ideas for doppelganger moves? Perhaps some fun ways to use Aid/ Interfere? What happens when the creature is inevitably discovered?