What happens if you shapeshift while bound?

[Petty Alchemy]

Say you've got rope and/or manacles on a guy. Surprise, he's a werewolf! Or maybe he's a druid. Something, and he tries to shift forms.

Now, I thought the polymorph descriptor had rules for what happens in this situation, but that might be a relic I recall from 3.x.

So, does shifting forms do anything to break bindings, or does it just fail if you don't have space to transform? Any SRD links would be helpful.

Thank you.

[EWHM]

The old 1st edition DMG had rules for how much damage you took if you were wearing armor when you transformed into a werewolf/bear/tiger/rat.
It usually wasn't a ton of damage--I think maybe d6+1 at most.

[ShadowcatX]

IMO, if he's shrinking, he'd probably get out. If he's getting bigger I'd probably give him a strength check (using his modified strength) to bust the chains, but if it didn't work his transformation would fail.

Of course, if the person / group that captured him knows he's a shape shifter, they'd take steps to counter that. (I read a story once where captured werewolves in human form were put in collars that had a small silver razor sharp strip inside the collar, if they grew larger and tried to pop the collar they'd decapitate themselves.)

[Trikk]

I'd use the rules from Enlarge Person:

d20pfsrd.com wrote:

If insufficient room is available for the desired growth, the creature attains the maximum possible size and may make a Strength check (using its increased Strength) to burst any enclosures in the process. If it fails, it is constrained without harm by the materials enclosing it--the spell cannot be used to crush a creature by increasing its size.

For smaller sizes you'd just have to go with your gut.

[Petty Alchemy]

What if he's not getting bigger or smaller? Just changing proportions.

[Fozbek]

Give 'em an Escape Artist check. The skill exists for a reason.

[Trikk]

Petty Alchemy wrote:

What if he's not getting bigger or smaller? Just changing proportions.

Then parts of his body are changing size, I'd say.

[Barry Armstrong]

Read THIS for what happens to druids if they shift while bound. Casting polymorph or shapeshift might be different, because spells and spell-like abilities work a bit different.