Captain Chronos (Created by Hero Games, property of DOJ, INC)

Time Travel: Time Travel can be accomplished in a number of mean. Most of

them cannot change the future, at least not to any great extent. Minor

changes can take affect, being absorbed by the time stream as a minor

alternate. Part of this effect is due to the Law of Observation. Any time

traveler returning to the past from his frame of reference, knows the

future. It is not a probability to him but a fact. Most beings will

subconsciously try to maintain there "reality" even if logically they want to

change it. It depends on willpower. An effect called Temporal Inertia also

plays a part. The time stream works against alteration. Slowly, ponderously,

never changing to much but resist change it does. This typically manifests

as "coincidence" working against the traveler, in other words Unluck. There

are ways around these effects, several in fact. Magical time travel tends to

ignore the Law of Observation, more so because mages are more used to

shaping reality with their wills and having it change on them. Temporal

Inertia can be defeated by careful, slow alteration and some means of time

travel don't invoke it at all. Still, the most secure means of altering

one's own past seems to be somehow manipulating agents from the time you

wish to change. From there frame of reference, the future hasn't happened yet

so it can be changed and they are "natural" parts of their time thus

circumventing the Observation Law and Temporal Inertia.