h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

1. The earth's orbit is not entirely consistant. Depending upon how far back you want to go, you are probably going to want to be in some kind of orbit, so you can catch up to the planet and enter the atmosphere, because...

2. Even if you do catch the planet at the right place, how do you know where in it's rotation you will be? Successfully travelling four hundred years is not going to be too fun if you need a parachute just at the moment you don't have one, or if you end up on the side of an arctic mountain or inside a lake. But, even if you do arrive on level ground in a temperate climate...

3. You have to worry about the pressure change between where you are coming from and where you arrive. You might arrive safely, but deaf.
You might arrive safely and hearing but blind. You might arrive safely and hearing and seeing but suddenly come down with the bends.

4. If you are going to be where people are, it pays to research the bathing habits of the time as well as the clothing. It also pays not to drink the water or shake too many hands. Dental health was a myth for a good portion of the human's time on this planet, so if you show up looking like 35 and you have the teeth of a ten year old, you're going to look suspicious.

5. Weapons. Learn to use weapons. Of any sort. And learn not to faint if you get wounded. The first ten hours are the ones to worry about with a wound. If you don't keep your head about you and deal with the possibility of infection, nothing else matters. Also, it probably would help a lot if you at least seriously disabled your attacker before running off to lick your wounds.

6. Language. Never trust the books. Learn as many languages as you can for the region you are going into and do a lot of listening when you get there.

7. Religion. Pick the right one. Remember it. Have some necessary artifacts with you. Do not engage in a theological discussion with anyone until you have half an illusion of who you are dealing with.

8. Sex. Find out as much as you can about the mores of the period.
Follow them or don't go.

9. Ignore the prime directive as often as you can. It was written by people who haven't been where you are. If you're lucky, you can kill their ancestors.

10. Stay away from major historical events. You'll just become disillusioned and get in the way. Many events were decades in the building up to and the results will find a way. Besides, everybody knows about the boring stuff. Go find something nobody knows about.

11. Don't go anywhere without backup. Always have a back door or a contingency plan.

12. Remember, you don't really know what you are doing. So, everything should be a surprise. Certainty can get you killed.

13. Oh, and leave the gold alone. It ain't worth it.

I love that!!!

Glad!

I am currently writing *two* sf stories about time travel. I have had to assert Amy's rule 4.
Your rules are great too, Tonsil.