Optional rules for D&D v3.5
Several attempts have been made to travel in time in D&D with more or less success. In a fantasy world where magic is real one would think time travel should be possible. The problem is how do you handle time travel in terms of the game.
Problems to Overcome
1. The time paradox problem.
What happens if you kill one of your ancestors? You would cease to exist thus undoing your murder which would bring you back into existence where you would travel back in time to kill your ancestor, etc. A paradox.
2. The interacting with your future self problem.
What if you meet your future self and touch? Some writers say there would be an explosion. Perhaps ending the universe..
3. The changing history problem.
Can you change history? One line of thinking says that you can’t change history, any attempt to do so will be foiled. Another opinion is that the moment you change history, a new branch of history is created. Every moment spawns multiple alternant future time lines, depending on the actions taken.
Solving the problems
In keeping with the principle that the D&D game should first be fun, and second should not unnecessarily limit what a player character can do, I propose the following time traveling rules.
1. There will never be a time paradox.
When you travel in time you can do anything you want and it will never cause a time paradox. This doesn’t mean that time travel is without risks, but you don’t have to work about accidentally killing your grandfather. I’ll explain later.
2. You will never meet your past or future self.
This is simple not possible. If you travel to a time where you have already been, you will occupy the body you had then. If you travel to a time you have never been before, past or future, your body disappears from where it is now and re-appears there.
3. Of course you can changing history.
What fun would it be to time travel if you couldn’t change things?
You can download a free copy of my time travel rules here: Time Travel