watch-dogs
When you kill or hurt civilians your reputation goes down, when you solve crime submissions or avert street crimes, your reputation goes up.
But: What is the actual point of the reputation? Does it have any influence on gameplay apart from being a motivator to do certain things and not hurt innocents?
The person playing Watch_Dogs on PC/PS/XBox gets an on screen prompt indicating that somebody is challenging them.
This prompt is only possible outside of missions, like the Fixer missions. Online modes only become available after completing the first few story missions up to and including the Online Contracts Introduction (which is when you first go through the tutorial for the one on one hacking missions).
It's all just flavour text. Sometimes on missions it helps you find your target, although the target, once profiled, will be marked either way.
Best Answer
With a low reputation, NPC's will sometimes recognize you and call the police.
With a higher rep, they'll still sometimes recognize you but they don't do anything game-altering. The comments they make are different.
Source: I had very low rep from running over so many pedestrians. I got sick of people randomly calling the police on me, so I stopped a bunch of crime and they stopped doing it.
I believe it also has a minor affect on the ending, but I haven't found a source to verify this yet.