Undead Should be Frightening

 Innumerable folks have pointed out that the undead in fantasy RPGs aren't particularly intimidating. Sure, they have a few immunities, but otherwise, a regular animated skeleton isn't mechanically much different that the garden variety orc. 

 Part of this problem could certainly be solved with placement. Again, as others have mentioned, let undead monsters rise up from pools of water or other airless spaces, to better emphasize their un-living nature. 

 One idea I've been chewing over, for non-sentient undead at least, is to change how they can be damaged. In movies, zombies can lose limbs, eyeballs, even legs, before they're finally stopped. You can beat the pulp out of them, but they still keep coming! Now, lots of rules systems have introduced various damage reduction schemes for undead already, such as skeletons taking half-damage from slicing weapons. But, I had an idea beyond mere damage reduction.

 

What if, after players roll their weapon damage, the GM rolls to see the effect. Something like, a 1d6 on a simple table:

1. Normal hp damage
2. Max 2 hp dmg; foot/leg damaged; MV reduced by 10'
3. Max 2 hp dmg; hand damaged; -2 on attack rolls
4. Max 3 hp dmg; head/face damaged; -4 on attack rolls; 
5. Max 2 hp dmg; arm damaged; -2 on damage rolls
6. Max 1 hp dmg; Non-essential body part damaged

Now, that could certainly make life more complicated for PCs and maybe put a little bit more fear into our players. Arguably, this makes non-sentient undead far deadlier, but shouldn't they be? Also note, if this were adopted, their XP rewards should be increased as well. I think I'd also disregard this table entirely, if the PCs were using burning oil in a fight.