1. Even though you think the monster is dead, NEVER check on it! Just keep on killing it!
2. Never read books about summoning the devil out loud, not even for fun.
3. Don't ever enter the basement. Especially if the electricity has gone!
4. If your kid should starts talking latin or other languages it shouldn't know; shoot it at once! Eventually this will save you from alot of trouble. (Be aware that the child could survive multiple shots before it dies, this includes children talking with someone else's voice.)
   
5. When you're many: NEVER walk alone to check out the environment.
6. In general, it's a bad idea solving riddles which opens a portal to hell.
7. Do not place yourself in, on or over a grave, crypt or other contaminations for dead people.
8. If you're searching for what it was which made that sound, and it turns out to be a cat; GET OUT!!!
9. If electric equipment starts all by themselves, don't start checking for circuit-errors, just get out.
10. Don't take ANYTHING from the dead.
11. If you enter an abandoned town, there must be a reason it's deserted. Don't stop to look around!
12. Don't f*ck with DNA unless you're absolutely sure you know what you're doing.
13. If chased by a monster, know that you'll fall a couple of times, and even though the monster could be slow or have a limp, it's still fast enough to get you.
14. If anyone in your presence behaves mysteriously (hiss-ing, fascination of blood, glowing eyes, growing bodyhair etc.) kill them!
15. Stay away from certain geographic locations. Here are some: Amityville, Elm Street, Transylvania, Nilbog, the Bermuda triangle and small towns in Maine.
16. If your car run out of gas on a lonely country road, you should not ask for help in the old house nearby. If you'd just filled the tank, you might as well kill yourself. You're going to be eaten and die.
17. If you find out that your house is built on or nearby an ancient indian graveyard, it's time to move in with you're parents in law.
18. Paragraph 17 is also valid in houses where previous owners have been mad, died/disappeared mysteriously and houses where devil-worshipping have taken place.
19. Always be sure to have a food and water supply for at least 5-7 days in your car. You'll need it. For economical reasons, bring a camera too.
20. If you feel that someone or something is watching you, always assume it is. Use caution while loading your shotgun.
21. Don't accept jobs where you and your family have to be isolated for longer periods of time, EVER!
22. If you're in any of the above situations; be prepared to die, 'cause you or your friend(s)/family will.

source: uknown, translated freely by Sigg3
#19, #20, #21, #22 by Sigg3