Time has its own momentum; some metaphysicians even postulate that it has a sense of consciousness. Disrupting the timeflow, therefore, is almost always vulgar magick, and moving it backwards is always vulgar, even in Sanctums or solitude. Yes, a Time-mage can perceive temporal flows without disrupting the timestream; once she chooses to mess with it, however, then Time itself reacts accordingly.

As noted in the Time Sphere entry, Paradox stacks up when a character goes backwards in time. Each successive increment of time compounds the Paradox involved:

• Turns: A character who rewinds time by turns adds one “layer” of Paradox per turn; if you go back three turns, then you incur three times the usual Paradox.

• Intervals: A mage who travels back according to the Time-Sphere Timelines chart gets two layers of Paradox for each interval on that chart; if you go back 50 years (or four intervals), then you get eight times the usual amount of Paradox.

Yes, that’s a catastrophic amount of Paradox. This is why so few mages even attempt such feats, even fewer succeed, and none perform them without great cost.

In many cases, a Paradox backlash linked to time-travel strands the mage in an alternate future or past… a trap from which she might not ever escape. Other backlashes could involve reverse aging (as Merlin is said to have aged); time-freezes; visits from Old Man Wrinkle or similar Paradox entities, as described in Mage 20, Appendix I; or the absolute erasure of the time-traveler from reality. A Storyteller for time-hopping mages is advised to keep a Back to the Future-type scenario handy for the inevitable screw-up, to get creative with the potential repercussions of Time-based Paradox, and to occasionally just say, “No, that didn’t work… or at least it didn’t work as far as you can TELL…”