Stolen from http://drcheckmate.wordpress.com/2008/10/30/have-a-happy-and-safe-halloween/

Some tips to keep us all safe this Halloween!

0. Do NOT under any circumstances whatsoever tempt fate.

1. When it appears that you have killed the monster, NEVER check to see if
it’s really dead.

2. Never read a book of demon summoning aloud, even as a joke.

3. Do not search the basement, especially if the power has gone out.

 
3a. Or closets or attics for that matter.

4. If your children speak to you in Latin or any other language which they
should not know, shoot them immediately. It will save you a lot of grief in
the long run. However, it will probably take several rounds to kill them, so
be prepared. This also applies to kids who speak with somebody else’s voice.

5. When you have the benefit of numbers, NEVER pair off and go alone.

6. As a general rule, don’t solve puzzles that open portals to Hell.

7. Never stand in, on, or above a grave, tomb, or crypt. This would apply to
any other house of the dead as well.

8. If you’re searching for something which caused a loud noise and find out
that it’s just the cat, GET THE HELL OUT!

9. If appliances start operating by themselves, do not check for short
circuits; just get out.

10. Do not take ANYTHING from the dead.

11. If you find a town which looks deserted, there’s probably a good reason
for it. Don’t stop and look around.

12. Don’t fool with recombinant DNA technology unless you’re sure you know
what you’re doing.

14. No, the previous number isn’t missing; Remember rule 0.

15. If you’re running from the monster, expect to trip or fall down at least
twice, more if you are female. Also note that, despite the fact that you are
running and the monster is merely shambling along, it’s still moving fast
enough to catch up with you.

16. If your companions suddenly begin to exhibit uncharacteristic behavior
such as hissing, fascination for blood, glowing eyes, increasing hairiness,
and so on, kill them immediately.

17. Stay away from certain geographical locations, some of which are listed
here: Amityville, Elm Street, Transylvania, Nilbog (you’re in trouble if you
recognize this one), anywhere in Texas where chainsaws are sold, the Bermuda
Triangle, or any small town in Maine.

18. If your car runs out of gas at night on a lonely road, do not go to he
nearby deserted-looking house to phone for help. If you think that it is
strange you ran out of gas because you thought you had most of a tank, shoot
yourself instead. You are going to die anyway, and most likely be eaten.

19. Beware of strangers bearing tools. For example: chainsaws, staple guns,
hedge trimmers, electric carving knives, combines, lawnmowers, butane
torches, soldering irons, band saws, or any devices made from deceased
companions.

20. If you find that your house is built upon a cemetery, now is the time to
move in with the in-laws. This also applies to houses that had previous
inhabitants who went mad or committed suicide or died in some horrible
fashion, or had inhabitants who performed satanic practices.

21. Dress appropriately. When investigating a noise downstairs in an old
house, women should not wear a flimsy negligee. And carry a flashlight, not
a candle.

22. Do not mention the names of demons around open flames, as these can
flare suddenly. Be especially careful of fireplaces in this regard.

23. Do not go looking for witches in the Maryland countryside.

24. The mentally challenged make vengeful ghosts and revenants, don’t mock them.