Corral

[Pasty_Hasty]

Can human players take boulders out of the corral and re-use them during a match?

[Aaron (Awe-Sum)]

Yes, that is how the boulders are re-introduced into the field.

[jee7s]

And they are required to be re-introduced to the field if there are more than 6 boulders in the castle, per G34.