Rainbow Six: Vegas 2 Cheats

Free MTAR-21
At the title screen hold R1 and press the following:

[Down]x2, [Up]x2, [Square], [Circle], [Square], [Circle], [Triangle], [Up]x2, [Triangle]: Unlocks MTAR-21 Assault Rifle

M468 assault rifle
Hold [R1] and press [Up], [Triangle], [Down], [X], [Left], [Square], [Right], [Circle], [Left], [Left], [Right], [Square] at the title screen.

Super ragdoll effects
Press Start to pause game play during an offline single player game, then hold [R1] and press [X], [X], [Circle], [Circle], [Square], [Square], [Triangle], [Triangle], [X], [Circle], [Square], [Triangle].

ACE and XP Farming
Found a spot to gain ACE and XP easily? Maybe guys are constantly dribbling down the fast lines and you can shoot them easily, or a bunch of terrorists are conveniently bunched up so you can kill them with a sack of C4.

Simply perform the actions you want for ACE and XP, then before you hit the next checkpoint, let one of those wannabe terrorists kill Bishop or Knight, forcing you to reload the checkpoint. You keep the ACE and XP you acquired (just don't turn off your system) and you can re-do that section again for more points.

Getting ACE Points With Teamwork -- Your Teamwork
Your computer allies are great for taking out enemies for XP, but not for acquiring ACE points. Keep them back if you can handle a firefight by yourself, since enemies killed by your team will not add ACE points.

Players who are using Bishop and Knight will gain ACE points respectively in co-operative Story mode. Just remember to keep the CPU team away. This does not apply for Terrorist Hunt and adversarial Multiplayer.