Energy Drain - How does it work?

[_Cobalt_]

The title says it all. I know it is channeled through attacks, but what does it do to the subject?

Thanks.

EDIT: Okay, I found it. For any who have the same question, the subject takes a -1 to attack rolls, CMB checks, CMD, saving throws, and skill checks per negative level from energy drain. It also loses 5 HP off of its maximum HP for each negative level it possesses. If the total negative levels exceed it's HD, it dies.

[Count Duck]

After 24 hours a character can make a Fortitude save for each negative level. For each failed save a negative level becomes permanent.

There is nothing more about it.