(Image Sources: Flash, Legends of Tomorrow)
Time travel on The Flash introduced us to e.g.
And in the episode Flashpoint (3x01) it is shown that speedsters will suffer memory loss when living in an alternate timeline for too long.
Barry has traveled back in time in several episodes, sometimes he seems to "merge" with his other self, sometimes he can interact with his other self, and sometimes we see his other self just dissapear into thin air.
However, in the pilot episode of Legends of Tomorrow Rip Hunter says:
We can't go back and change events in which we participated. Time would fold in on itself, creating a temporal vortex.
Time Wraiths and Time Remnants don't seem to be in issue on "Legends", but it is shown that changes in the timeline take time to "solidify", giving our heroes only a short window in which they can reverse the changes before they become permanent.
I have heard people argue that "Legends" uses technology to travel in time, whereas Barry, and other speedsters, use the speed force, hence time travel works differently in both shows, even though they are both part of the Arrowverse.
And to complicate things further, the "Legends" episode Out of Time (2x01) has revealed that there is actually a speedster messing with their timeline now.
- Are the time travel rules different for both shows, or is there an in-universe explanation to reconcile the differences (e.g. technology vs speed force)?