The Doppelganger Problem
The Shadowdark Doppelganger is a 4 HD monster with two +2 claw attacks for 1d8+1 each, which is the part people fixate on and the part that matters least. Its real weapons are two abilities. Change Shape lets it spend its action to assume the form of any creature it has seen, which costs it an attack but buys it a disguise. Telepathy lets it read the surface thoughts of any creature within Near range, which means it knows your stated plan roughly when you do.
That second ability is the one parties misjudge. If the group huddles and debates for ten minutes, the Doppelganger (if it is present in some borrowed shape) has read every word of intent and already knows who suspects it. Deliberation is a gift to the thing that reads minds.
The counter is tempo. Keep moving so it must stay inside Near range to listen, then force it to act before it can settle on a convincing form. A Doppelganger that has to transform under pressure spends its action on cosmetics instead of claws.
At the table: Put a ten minute real-time sand timer on each in-character planning phase. When it runs out, the party acts on whatever they decided, surprises included.
Related
- The Monster Has a Plan Too
- Stat Blocks Lie: Monster Tactic in DCC
- Making an Attack Is Not the Attack Action
Daily field notes, weekly Issues. Follow @ItsAlrdyWritten or subscribe via RSS.