Horde encounters.

[Chadamantium]

So I was reading FFN and it was talking about treating the HP as a direct indicator of population of enemies to create horde encounters.

http://ffn.nodwick.com/?p=1287

Has anyone ever done something like this and how should I go about implementing it for 3.5/pf.

[Slipperychicken]

You could check out DMG2's Mob Template.