Is Ray of Enfeeblement too good?

[Mistwell]

Monte Cook's Arcana Unearthed/Evolved has a spell called Burden that adds weight to the opponant, and specifies the rules for being overly encumbered. It says that if the target goes over heavy, they suffer max dex, check penalties, and speed reduction. If they go twice over max load, target can only move 5 feet per round as a full rond action, and loses all dex bonus to AC. If target goes 5 times over max load, target cannot move and is helpless.

 

[Zoatebix]

And I'm pretty sure weight limits and their consequences are the same as those from the adventuring chapter for lifting things off the ground and pushing/dragging heavy things.