Rule 1.
Kill it.

Rule 2.
If in doubt kill it.

Rule 3.
Just to be sure, kill it again

Rule 4.
See rules 1 through 3 and repeat until it is dead.

Rule 5.
If its dead, cremate it straight away. You don’t want the undead coming back and be made to kill it again.

Rule 6.
If you killed it, all its stuff is yours.

Rule 7.
Kill em before they try and kill you. (NPC and PC alike)