A mayhem mission is where you enter an instance of a Paragon city zone and try to rob a bank. You have only 15 minutes to do it, but if you do, you get temporary powers which are actually very useful (particularly the ones from the level 5-10 and 11-15 that give temporary travel powers (see details at Paragonwiki)
To get a Mayhem mission (usually abbreviated as mayhem), you have to do a certain number of Paper missions. Once you have done the correct amount, you'll be unable to use the paper again until you talk to a broker (whichever one is named when you try the paper).
Unfortunately, no matter how much you've done for him, you'll have to walk all the way to him to get the option for the mayhem (apparently, they don't have cell phones). If you don't want to do it, you can decline and you can take paper missions again for a while.
If you accept, you can do the Mayhem which is the counterpart to the Heroes' SG. The advantage to the Mayhems is that there are badges to be had and you can get various temporary powers from completing them or the side-missions therein (details here).
Also note that while it's very, very annoying, you MUST return to the broker after completing an mayhem or he'll sit there like a wet turd taking up room in your missions list forever. Just go talk to him and he'll thank you and offer to introduce you to some new contacts (which is a great way to find new story arcs to follow if you otherwise ran out or outleveled the ones you had before). |
Most every detail about the rewards and such for Mayhems can be found at Paragonwiki so I won't repeat that here. Instead, here are some gameplay tips: