Jun05
on June 5, 2014
Twinned
The odd thing about doppelgangers is all the work that has to be done to pull off a monster that makes itself an identical copy of a Player Character. They have to read minds to know all those secrets, they have to copy clothing, it can use magical items like the original, and so much more.
Of course, this never works because it takes the party ten seconds to ask the duplicate to cast a spell or drop their sword on the ground. It’s possible for a GM to trick a player, but an entire party is so much harder: it’s four against one.
This is why a properly-run doppelganger doesn’t mimic a PC in front of their friends. Rather, they look like someone the group will want to take along (say, someone in need of rescue), and wait until they can catch one of them alone. Kill or incapacitate the character, take on his looks, put on his gear, and rejoin the party. Isolate another one, rinse and repeat.