Assault waves...
	Finding important people...
	Special enemies...
	Various Steam Achievements...

Throughout the game, occasionally your contact will say "An assault is coming in X seconds." Listen carefully to what he says. It is a hint of special units coming in, and when the assault will begin. Each wave lasts for approximately five minutes, depending on how many officers you kill. If you need to complete a time consuming objective, such as making sure the saws in the Panic Room are going, camp somewhere near there so you can hold out easier and get the job completed. Note: Some missions have "escape" objectives, which means the wave will never end until you either complete the mission or die. You will know when this happens depending on the mission and what the contact yells.

If you need to find a bank manager or someone who has important items, wait a few minutes, and the game will display that person in orange through walls. They should be taken hostage, as they sometimes count as civilians, and can easily be found.

There are numerous special enemies that can be difficult to kill. You can see them and defeat them more easily by using the shout-out command while aiming at them. Here are some of the enemies and what they do:

Bulldozer: Large bulky enemies covered in thick armor. They do massive damage if they get too close and require a lot of bullets to kill. All fire should be focused on them the moment they are identified. Headshots will help.

Shield: Black officers who have riot shields in front of them and try to move up. They can be flanked easily and taken out from the side and back. Bullets will not harm them in the front. They are very deadly while in a hallway.

Sniper: Although not a "Special Unit", they are deadly. Two shots will drain your health. Either avoid them or take them out.

Spec-Ops: Agents wearing green night-vision goggles. They will handcuff you to the floor if they get too close. It is recommended that you take them out immediately.

Taser: Police who wear yellow stripes. You will hear him charge the tazer before firing at you. If shot, you will be unable to do anything but look around while your character randomly fires at them. Try to aim at them in this state. If tazed for too long, you will go down.

Complete the indicated task to unlock the achievement.

Achievement	How to unlock
A bridge too far!	Finish the GREEN BRIDGE on hard or OVERKILL difficulty. You must have played the heist from the start.
Are there more than two?	Find ten money bundles in PANIC ROOM.
Are those the blue ones?	Steal all the sapphires in DIAMOND HEIST on hard or OVERKILL difficulty. You must have played the heist from the start.
Are you ready yet?	In DIAMOND HEIST, get Bain to come back for you at least 7 times. You must have played the heist from the start.
Blood in, blood out	Trade all the butchers in SLAUGHTERHOUSE. You must have played the heist from the start.
Bomb man	In DIAMOND HEIST, defeat all twelve Patrol Guards using only trip mines. You must have played the heist from the start.
But how?	Get the armored car to drop without shooting at it in SLAUGHTERHOUSE. You must have played the heist from the start.
Cheney?	Defeat a Bulldozer with a shotgun.
Civil disobedience	Defeat 100 law enforcers in a single heist.
Crack-bang	Gain a level in the Sharpshooter tree with your last kill being a Sniper.
Darkness	On GREEN BRIDGE, destroy all the lights in the main scaffolding tower. You must have played the heist from the start.
Diplomatic	Perform a hostage trade.
Dodge this!	Beat a heist on norm difficulty or above,having killed a Bulldozer w/o taking damage from any Bulldozer.You must have played the heist from the start.
Don't lose face	Beat all heists on OVERKILL difficulty without anyone getting traded from custody. You must have played the heist from the start.
Eagle eyes	Point out a special enemy using the 'shout out' command.
Easy street	Beat HEAT STREET on OVERKILL difficulty,w/ your group accuracy being at 60% or higher. Everyone in your crew must have played the heist from the start.
Federal crime	Defeat 25 FBI agents in a row.
Gold digger	Beat SLAUGHTERHOUSE within 15 minutes, taking all the gold. You must have played the heist from the start.
Hot lava	Don't let any law enforcer reach graffiti on center roof in PANICROOM from SECURE ROOF obj.until ESCAPE obj.on hard or OVERKILL diffi.Heist from start
I ain't afraid no more	Gain a level in the Assault tree during an assault.
I pushed the button and lived!	In DIAMOND HEIST,get the big diamond and escape on OVERKILL difficulty w/ you and all your team mates alive. Must have played the heist from the start.
Intimidating	Get a Heavy SWAT to give up.
Last man standing	Beat a heist after having been the only one alive.
Lay on hands	Gain a level in the Support tree while reviving a teammate.
Left for dead	Finish a heist in custody while all your team mates are alive.
No photos	Destroy all the cameras in FIRST WORLD BANK within 10 seconds of drawing your weapons. You must have played the heist from the start.
Noob herder	Beat any heist on OVERKILL difficulty with three other players who are all using the Noob Lube perk. You must have played the heist from the start.
One shot, one kill - repeat	Get 30 kills using 30 shots, using only the M308 Rifle.
PAYDAY	Aquire one billion dollars in total cash. One. BILLION. Dollars.
Quick draw	In PANIC ROOM,kill all armed thugs in&around apt.building within 60 sec of you&your crew drawing weapons. You must have played the heist from start.
Shinobi	Bypassing all 3 consoles before raising the alarm, beat DIAMOND HEIST on hard or OVERKILL difficulty. You must have played the heist from the start.
Stand together	Beat HEAT STREET on normal difficulty or above without anyone getting downed. You must have played the heist from the start.
Windowlicker	Defeat a law enforcer planting C4 in FIRST WORLD BANK on hard difficulty or above. You must have played the heist from the start.
You can run but you can't hide	In PANIC ROOM, take the key from Chavez within the first 45 seconds of starting the mission. You must have played the heist from the start.