very helpful guide four thumbs, two claws, and a prehensle tail up.
There used to be, I wrote one when Mayhems first came out but I guess it got tossed. Oh well, I still found your guide to be helpful to good on ya 
High Beam - 50 Blaster Energy/Ice - 1228 Badges
Munitions Mistress - 50 Mercs/Traps
Many Other 50's, Too Many Alts, All On Freedom
Just Because You Can, Doesn't Mean You Should!
Found it.
High Beam's Guide to Mayhem
High Beam - 50 Blaster Energy/Ice - 1228 Badges
Munitions Mistress - 50 Mercs/Traps
Many Other 50's, Too Many Alts, All On Freedom
Just Because You Can, Doesn't Mean You Should!
Update: Destroying objects after robbing the bank adds time. Don't know if pre-I7 it was different, but now it does.
I can't believe there isn't one of these yet, but from what I see playing the game, a lot of villains still don't understand how mayhem missions work. This is a collection of my experience soloing this missions (and some group experience), so take it at that. I hope this guide helps some folks; mayhems can net you nice experience and infamy and its a shame that so many fail doing them.
General
Most folks know you get mayhem missions from your broker after every 3 (or more at higher levels) newspaper missions. You have a time limit of 15 minutes to pull a bank robbery and take out a hero. If this is all you do during the mission, you're going to run short on time, and you're missing half the fun.
First off, you get bonus time by destroying a specific number of objects of a particular type. The number varies depending on how many are in your group, but once you've destroyed the requisite number, you will not get any additional time by destroying more of them.
At lower levels you need to focus only on the easy stuff because the bigger objects may take you more time to destroy than you get back in bonus time. For example, most Atlas Park folks will ignore PPD SWAT Vans, Trucks, Large Metal Crates, and probably Cars, as it will take too much time to destroy these.
From easiest to most difficult (imho), the object types are:
<ul type="square">[*]Cardboard Box - level 1, 10 hp, destroy 5 when soloing for 1:00 (this includes Large Cardboard Box)[*] News Vendor - level 3, 20 hp, destroy 1 when soloing for 1:00[*] Pay Phone - level 3, 20 hp, destroy 1 when soloing for 1:00[*] Mailbox - level 3, 30 hp, destroy 1 when soloing for 1:00[*] Parking Meter - level 3, 20 hp, destroy 5 when soloing for 1:00[*] Dumpster - level 3, 115 hp, destroy 1 when soloing for 1:00[*] Fire Hydrant - level 5, 45 hp, destroy 1 when soloing for 1:00[*] Trash Can - level 5, 20 hp, destroy 5 when soloing for 1:00[*] Barrel - level 5, 45 hp, destroy 5 when soloing for 1:30; note that these cause a small explosion[*] Bus Stop - level 8, 70 hp, destroy 1 when soloing for 1:00[*] PPD Car - level 10, 195 hp, destroy 1 when soloing for 1:00; these explode![*] Crate - level 10, 90 hp, destroy 5 when soloing for 1:30[*] Car - level 10, 195 hp, destroy 5 when soloing for 3:00; these explode![*] Large Metal Crate - level 15, 265 hp, destroy 1 when soloing for 1:00 (aka Cargo Crate)[*] Truck - level 15, 265 hp, destroy 1 when soloing for 1:00; these explode![*] PPD Van - level 15, 265 hp, destroy 1 when soloing for 1:00; these explode![/list]You get credit for items destroyed by NPCs as well. You'll see this sometimes when you get bonus time for no apparent reason.
Soloing Guide
The first time you run a mayhem mission, I recommend soloing it, or with one other person. Unlike many missions, these are easier the smaller the group is, and you want the best chance at grabbing the temp power first time through.
Once in a mayhem your tactics depend on your character. If you are primarily melee then you want to take out police before any objects near them. If you use ranged attacks you want to destroy explosive objects near police to soften them up and then go for the kill. Destroying a car (for example) next to a police officer will not aggro the police officer, but it may damage, kill, stun, and/or knock him back.
The first thing I do when I arrive is to shoot at the nearest police car. This gives me an idea of how long it will take to destroy one so I know whether or not to bother with other cars, trucks, or swat vans. At higher levels I don't need to bother with this, but early on it helps a lot.
My first goal is to work my way towards the bank, destroying objects as I go to collect time (but not more than needed) and eliminating police groups along the way. Every map has spots on it where Longbow are summoned to give you grief, and you'll know these when you hear the "Halt, Longbow!" (The only reason you'd actually halt is to see where they're coming from and get ready to kill them.) These Longbow always seem to know where you are, whether you're stealthed or not, and they will follow you into buildings and up elevators.
While en route to the bank, you'll want to watch for critters other than cops and longbow. Often they'll give themselves away by talking when you get near (watch your chat window). Track them down and kill them to get a key. You will find one group per side mission, and the number of side missions seems to depend on the level (e.g. Atlas Park has one, Kings Row has two, etc.). Once you get the key, look in your Clues window to find out what its for. Your first time through you'll probably want to save these for after the bank heist just to ensure you get that done first. (The exception may be for jail break, since you can get a helper for the heist that way, and you have to do it anyway if you die.) The type of critter also seems to depend on the area; I've seen Skulls, Clockwork, Council, Family, and Freakshow.
If you make it to the bank and still have items to destroy, you might want to hunt around and finish your list, ignoring anything too difficult. You will not get bonus time for destroying items after the bank robbery, so collect it now.
Pulling the Heist
First off, make sure you've finished off any Longbow or police that have followed you to the bank. You don't want to get into a firefight only to find yourself outflanked. Did I mention they will follow you into the building?
Take a peek into the lobby; often it is crowded with shaky citizens which can make targeting security and police difficult. If you have a ranged attack you can make without getting near any guards, pop a citizen in the head. They'll run out, along with a few others. Keep it up and you can clear the lobby (and bank) of those annoying targetable non-targets. If you're a melee type, just run in and pound on the nearest security guard. The citizens will flee in terror, but they can still be annoying as they make for the exit.
Next, clear the lobby of guards and police. This is often the biggest fight you get into on the way to the vault, but it depends on where the guards are at. There is usually one boss group in the bank.
Work your way to the vault (sometimes on the second floor depending on the map), cleaning out guards on the way. If you can stealth by them, that works too, but you'll want the area near the vault cleaned out.
When you reach the vault door, an ambush is triggered. After a minute (approx.) you'll have a group of security show up. As with all ambushes in mayhem, they seem to see you even if you're stealthed. After you destroy the vault door (or half destroy it, not sure which) two more ambushes are triggered - groups of police will show up to "arrest" you. At the higher levels I think its three ambushes. These are timed, so you can easily get overwhelmed if you're still beating up the first group when the second shows up.
When you actually pocket the money, you trigger the final ambush - the hero and some longbow. You need to kill the hero and longbow to have a successful mission (hero alone doesn't cut it). You do not have to kill the police or security guards, but it often pays to do so. If you have the time, go ahead and wait for the police ambushes before you trigger the hero ambush. If you're short on time, you can trigger it right away, and the hero generally shows up with the first police ambush.
Jail
If you die and opt to go to the hospital, you end up in the PPD Jail. There is a dampening field in the cells so your friends can't teleport you out. The first thing you do is start smashing down the reinforced door that's keeping you in your cell. Unlike other prisons, these cell doors don't explode when you defeat them.
If one of the side missions is a breakout, then you'll find yourself with a boss group of police in front of the villain's cell. They have no qualm about taking you out, so that will be your first fight.
There is an ambush spot right in front of the elevator down; this summons a group of longbow who will show up in about 30 seconds. (They spawn somewhere outside and head into the police station from there.)
After the elevator down, there is almost always a group of police waiting for you at the bottom. You may have to fight through another group or two to get out of the station itself. Don't bother following the yellow line out -- it takes you to another reinforced door. Its faster to go around than it is to pound it down. Reinforced doors scale in level with you, much like vault doors, so they never become cake to smash open.
Arson
The arson side mission nets you 4 minutes of bonus time. All you have to do is set five bombs in the lobby of a building. After you enter the building a longbow ambush is triggered. You might get one bomb set before they show up, but usually not. After that there are two more timed ambushes of police (three at higher levels). Once all bombs are set, the building catches fire. Get out or get burned. Even outside there are some fires so don't stand too close to the building.
Breakout
The breakout mission involves busting a villain out of jail. This is the only side mission you don't have to get the key to complete (you can enter the police station at any time), and it is the one you will face directly if you die. Refer to the Jail section above on the groups you will face. Successfully killing the boss group in front of the villain's cell gets you the bonus of 3 minutes. You don't even have to bash down the cell door, but if you want the pet you have to.
The villain pet barely qualifies as a moron. Once outside they have the tendency to run around destroying things, often getting themselves blown up in the process. Other times they'll just stand there staring at an object and won't do anything until you destroy it for them. Finally they tend to get lost very easily, and you have to go find them to get them to follow you again. If you can manage to get them to the bank, they can be helpful in defeating the guards and hero (if they survive that long). The mastermind "attack my target" command does seem to get them to beat up what you're targeting, but beyond that they seem uncontrollable.
Kidnap
The kidnap side mission is the most time consuming of the lot, but you get 8 minutes for completing it. Still, it may not be your cup of tea. The victim is inside the office building guarded by a boss group of police. There are other groups of police between you and them as well. There is also a Longbow ambush when you first enter the building. Clear a path, take out the boss group, and lead the victim out of the building. Continue leading them all the way to the mayhem mission exit. There are 2-3 police ambushes triggered here as well, but often I don't encounter them until after I've completed the kidnap. Keep an eye out for them; you don't want to get put in a bad spot.
Raiding
The raiding side mission is the one that generally nets you another temporary power. Somewhere inside the warehouse is a box of goodies, yours for the taking. The warehouse will be guarded, but it could be any critter type and usually is not the same ones you encounter outside. You don't have to defeat any of them to get the goodie and the 6 minutes that comes with it. There is one Longbow ambush triggered when you first enter the building, but no others.
Smash and Grab
The smash and grab mission can get you the most time, but it can get you in the most trouble too. Upon entering the building there is a Longbow ambush triggered. After that, any time you trigger an alarm you're rewarded with another Longbow ambush. In addition, if you trigger any alarms, at some point you will get 2-3 police ambushes, often very close together. To further complicate things, there's generally 3 groups of security guards in the building as well. The first part of this mission is to dodge the alarm beams and open all of the wall safes. Completing this gets you 5 minutes.
Next there will be a pair of "blinkies" either behind a vault door or a reinforced door. That door is generally protected by a pair of alarm beams, so it is rare you can blow the door and get in without triggering the alarm. The blinkies are typically display cases or floor safes. If you're quick, you can get both of them before the ambushes show up. Collecting those two gets you another 6 minutes (for a total of 11 minutes if you did both parts). I also seem to get an enhancement when completed (something generally useless, like a DO range increase).
Some tips: if you're a mastermind set your minions to stay by the door (or in a group keep everyone else by the door). They can beat up the Longbow ambushes as they come, though they'll need all the help they can get when the police show up. It also keeps them from mindlessly wandering through an alarm beam. Also, watch the alarm beams before you head in. They sweep back and forth and leave big gaps you can exploit. Often you can open wall safes by standing in an area the beam never reaches, or otherwise opening them when the beam is sweeping away from the area.
Group Mayhem
I have to explain this almost every time I group in a mayhem mission. Group mayhem is more difficult than solo mayhem. There are four reasons why: first, you still get only 30 seconds for resisting arrest, but generally it starts taking longer than that to wipe out police and Longbow groups, especially at levels higher than villainous. It also means more things to destroy to get a time bonus.
The second reason is focus -- you have to have a plan for completing the mission because it is too easy to get distracted fighting all those police on the way to the bank. A good plan is to fly over everything and land at the bank, or have a stalker zip there and teleport everyone there. If you want to fight the whole way then you will need to be sure your team can kill things quickly. You also need to keep the team close together. If they spread out you easily end up with more than one group engaged, and can they trigger unexpected Longbow ambushes.
The third reason is related -- death. When a team member dies and they can't be awakened on the spot, they end up in jail. This means the team must detour to the jail and help them break out, since chances are they won't be able to fight their way out alone. This eats up a lot more time than you might think. Subsequent deaths are easier since the police station is cleared, but they still may need help bashing down a cell door.
The fourth reason involves slow loaders; often you sit around waiting up to a minute or more for the guy with the 486 and 300 baud modem dialed in from Elbonia, and time is precious in a mayhem mission. A solo slow loader doesn't impact themselves since the timer starts when they finally load, but for a group the timer starts when the first member loads. The way to help alleviate this is to have the slow loaders enter first, and the quick ones wait before jumping in. Also make sure everyone is ready before beginning the mission. The last thing you need is Dr. AFK to say "brb bio #2" while Captain Slow Loader has just jumped into the submarine.