Forced pooling is the concept that forces landowners to allow drilling under their property if enough of their neighbors have signed leases. Many people (PA Gov. Tom Corbett and MDN among them) think it’s not a good idea—calling it the equivalent of “private eminent domain.” But the reality is, it does widely exist. In fact, forced pooling exists (by various names) in all of the Marcellus Shale states except Maryland.
In New York and Pennsylvania its called compulsory integration. In West Virginia its called mandatory pooling, and in Virginia its called compulsory pooling. So when you hear those terms bandied about, it means “forced pooling.” A special note: Forced pooling provisions in both Pennsylvania and West Virginia do not (yet) apply to Marcellus Shale drilling, but proponents are trying to make it happen in those states.