Cops 'n Crooks involves players being split into 2 teams: The Crooks, or the criminals and the Cops, or the police. The crook players are attempting to escort their boss (or themselves) to safety whilst evading the cop players, who are trying to kill them. There are two modes: One for All and All for One.
All for One
In the All for One version, the boss must attempt to escape to the getaway vehicle with aid from the crooks. The cops must attempt to kill the Boss or destroy the getaway vehicle. The crooks hold no importance when escaping, therefore, there is no need for them to escape with the boss. The Boss must stay seated in the getaway vehicle for approximately 8-10 seconds.
In all for one, the crooks may choose to generate a certain amount of money until they depart; this is done by taking out cops which give $100 per kill and can be done an infinite amount of times until all the cops leave. If the Boss manages to escape, the crook team will gain $1000.
Cops can also gain $1000 by taking the boss down, although, many people prefer to accumulate more money by taking down the crooks which can also be done an infinite number of times until they leave the game unexpectedly, the boss is the only one who will not respawn. When the boss dies by any means the round will automatically finish within 3-5 seconds, athough dying without being killed may result in "-$100". You may get extra cash by collecting cash dropped by the cops and the crooks when they are killed.
One for All
The One for All version has no Boss to escort, simply the Crooks keeping themselves alive and attempting to fill a getaway vehicle with teammates to win, either a boat or a helicopter. Only 4 Crooks can escape in the getaway vehicle. Once the getaway vehicle is full or all the remaining Crooks are in, they must stay seated for 8-10 seconds so the round can end. Any remaining Crooks members can either stay behind and fend off Cops or run like a renegade to stay alive until the round ends!
The Cops players win by killing all of the Crooks before they can escape. Crooks can also win by killing all the Cops. Each opponent you kill is worth $100 for your team. Killing all of the opposing team is worth another $1,000! Each Crook that escapes in the designated vehicle is worth $250, meaning a full 4-seater boat/chopper is worth $1,000. Dying on your own, like a long fall or blowing yourself up will cost your team $100, just like in All for One.
Players can NOT respawn in this mode. Once a player dies, they have to wait for the round to end.
- When the cops are traveling to the crooks' position, Police Cruisers with their emergency lights flashing and engine on may randomly spawn in the middle of the road. This glitch only occurs at the beginning of the round playing as a cop. This does not always happen.
- A much more rare glitch occurs in which NPC police may spawn in traffic. Players as crooks will not earn a wanted level if they are in sight. Shooting at them will have no effect. They also do not assist with the "Player cops" in any way.
- Austin, Texas-based Achievement Hunter has done Cops 'n' Crooks in five of their Let's Play videos. Four of those games (Parts 1-3 and Retro Play) were the standard Team Lads vs. Team Gents alignment; Part 4 had them repeatedly switch teams. Part 1 noticeably saw all but one round go to Team Lads (including two RPG triple kills by Team Lads as the crooks, in rounds five and eight by Ray and Michael respectively; their third member, Gavin, was in a different vehicle both times and was also blown up by an RPG while driving a cop car, in round six).
- Respawning in the general area of an opponent can be an issue, as evidenced in Let's Play GTA IV Cops 'n' Crooks Part 1's fourth round when Geoff, after getting killed by Michael who had been chasing him and Ryan, respawned while Ryan drove by and Michael promptly ran him over (which resulted in Geoff yelling "BAD SPAWN!!" despite surviving). Round four also happened to be Ray's 'Moto-Cop' round (he left the cop car early when Gavin, who was driving, kept hitting stuff, found and commandeered a motorcycle, and successfully caught up to Jack after a few minutes making Jack's car explode with Jack in mid-bail for a Team Lads victory).
- Perhaps the best way to win in One for All Cops 'n' Crooks is to have four or fewer players on the cops team and blow up their car, with them all in it, with an RPG. In All for One an all-cop-blasting RPG shot could potentially give the crooks enough time to escape before the cops can manage to find a new car (a problem Team Gents had in a few of Part 1's rounds - immediately confronted by Team Lads in round two, as the crooks; happened again in round four but survived longer until Ray Moto-Cop'd Jack; couldn't find a vehicle in round five after Ray blew their cop car up (especially harsh as Ryan had put traffic on high, too); and had to put two guys on one bike after the cop car exploded via Michael with an RPG in round eight).