The anorak within came out in me when it fell to writing Eternium, and in particular I wanted to have the game universe able to convey some authority to gamemasters who might need to set up time travel adventures in groups where they had one or more tiresome players quick to find fault. Accordingly, I surveyed the media involved- chief amongst the spectrum, Doctor Who and the Time Machine- and wrote up definitive Laws of Time. That way, there was something for time travellers to quote.
Steamtown will feature a chapter on the Laws of Time as well as namechecking them a couple of other times.
From Eternium, First Edition, pages 208-210
Law 1: THE PRESERVATION OF THE ENERGY OF INFORMATION
The difficulty of changing an event in a specific time period varies with the square of the amount of knowledge relating to that event.
Law 2: THE PRINCIPLE OF ORTHOGONAL HISTORICITY
The tendency of any timeline is to follow it most likely thermodynamic and chronodynamic track, and its applicable laws of physics and sociology will dictate the degree of change possible by someone entering the reference from another time period.
Law 3: THE LIMITATION PRINCIPLE
The number of basic changes to any event is limited by the relative certainty of the event. The chance of successfully changing an event varies with the inverse square of the number time travelling attempts to alter it.
Law 4: THE DIRECTIONLESS MOMENT
Time's smallest measureable passage has no objective direction. For any moment, there is at least one supporting moment, but this relationship does not imply a direction of flow of time.
"History is nothing more than imperfectly remembered dream"
Source: ETERNIUM
