The following is a walkthrough of the mission Three Leaf Clover in GTA IV.
Before the mission (as you're driving around), Packie will SMS you about wearing a smart suit and shoes from Perseus. Listen to him or the mission will not start. You also cannot start the mission between 7 pm and 6 am. When you arrive at his house, you will meet Derrick McReary, Gerald McReary, and their friend Michael Keane. Gerald does not take lightly to Niko being involved in the family business and reminds Niko that Derrick has returned. After the cutscene, Packie tells Niko to get a car with four doors so they can all fit.
Find a vehicle with four door and drive to the Southern Algonquin branch of the Bank of Liberty. A cutscene will show Niko, Packie, Derrick, and Michael Keane threatening all the customers to get on the floor of the bank. Luis Fernando Lopez and Eugene Reaper will be laying on the ground whispering about Eugene having a gun on him and Luis telling him not to do anything. Derrick and Packie have an argument, giving the chance to shoot Michael and kill him. Packie and Derrick kill Eugene in retaliation. The team then blows up the vault door.
Head down into the vault as inquired and grab $1 million for your teammates. NOOSE and FIB police officers arrive at the scene with helicopters and cars, prompting Packie to decide that they need to leave now with the money they have already collected.
Niko, Derrick, and Packie take cover at the front of the bank and begin to gun their way out of a five-star wanted level level. Due to the heavy presence of heavily armed officers and vehicles, you must be careful with your Health and Armor. There are roughly 16 standard cops spread out over the street. The best way to take these and other officers in this mission out is to shoot at the police cars' gas tanks, located behind the rear wheels. If flames start coming out of the gas tanks, they will blow up in short time, but you may continue firing to cause an immediate explosion. The explosion from the cars will kill any nearby officers and knock others to the ground, and possibly ignite other cars. Any remaining officers are best dispatched by a shot to the head, especially so for the otherwise heavily-armored NOOSE officers. Being equipped with a rocket launcher and grenades is also very helpful.
Help your remaining teammates shoot their way through an alleyway. Gain protective cover and blind fire the 12 men of authority. You must then proceed through three streets in Chinatown, but not before shooting a loaded cop car that obstructs their path to the three streets. The first street you come will have two cars (one NOOSE and one normal police car) with about 6 men in total. Get cover in a side alleyway, like your teammates, and pick off the men with a headshots to conserve ammunition. The second street has the most amount of cops in the level, so it is wise to take excellent cover, possibly behind a burnt out car. There are cops on fire exits above the streets, and several men on the ground, around 30 cops. You can just spray them with a Sub Machine Gun so as not to waste M4A1 bullets. The final street is the easiest as there are almost no men, and you can quickly run across the street and into the alleyway ahead of schedule. There are several cops on the street, but as you are sprinting it is unlikely they will hit you. The trio are trapped out in an open alleyway by an police helicopter and the team attempts to shoot it down. It stays hovering, leading Packie to save the crew by taking them into a subway station.
Two police officers are waiting for them down in the station. Packie and Derrick jet by them but you should shoot them down with a pistol headshot, or you can just ignore them as they will not follow you down.
When you enter the subway gates, there are two cops shooting at Packie and Derrick so take them out with a quick headshot while they are standing still. The next part of the subway consists of killing four cops waiting for the group in cover behind some gates. After dealing with them eight NOOSE officers storm up the stairs. At this point you should aim to kill as many of them via headshot as possible, and taking cover if any are left, because they are very deadly in such close proximity. There is a first-aid kit on a pillar here, which you can use to get back to full health. Go down the steps and into the subway to escape. There are 8 cops across the tracks in a group. They are easily taken out by something such as the rocket launcher as they are close together and at safe distance, otherwise aim for the head as usual. When you get onto the tracks 10 NOOSE officers try to follow you. You can kill them, but you can also leave some of them as eventually Packie and Derrick are going to make a run for it. When you flee through the subway tunnels, be aware of metro trains which might cross your path. Being hit by a train leads to immediate death. Also note that the trains run on left track, instead of the right track as usual. So if you walk on the tracks, you'd better walk on the right track, so you can see trains approach. This is the final encounter with police until you get topside, all the while Packie and Derrick argue about Michael's death, with Niko telling them to shut up. Eventually, Packie leads the team back to the surface via a maintenance entrance in Easton, by which time the wanted level has been reduced to only three stars, which is fortunate as your ammunition or health may be low by now.
Once outside, a parked Huntley Sport is available for you to steal (easier said than done, however, if a police car is stopped nearby as either Niko runs the risk of being arrested or the action of making him steal the Sport will make him steal the police car instead (fortunately, it's usually a 4-door). The objective now is to lose the wanted level, this can be done as normal (however, the GPS is misleading when it comes to guiding Niko onto the nearby Algonquin Bridge; it is extremely easy to head down the wrong track and be cornered by the cops. Crashing through a police barricade is also necessary; this, coupled with collisions on the bridge, makes damaging out the stolen vehicle a real danger and this almost guarantees mission failure.
When they finally lose the police, Packie asks Niko to take him and his brother Derrick back to his Mom's house in Meadows Park, Dukes (on Savannah Avenue near the Monoglobe). On the way, Packie explains how they will split the money. Niko, Packie and Derrick get $250,000 each. The remaining $250,000 will be given to Michael's parents since he died in the heist. On average, Niko, Packie and Derrick will kill about 100 cops, however it is possible to kill a relatively small amount of cops by ignoring some of them and going for less-lethal shots with others.
- When you and your team reach maintenance entrance in Easton, by which time the wanted level has been reduced to only three stars, you can go back to the subway tracks, and easily escape the police. This strategy is helpful for players that have problem with evading police after exiting metro system. Be careful not to run into subway trains; normally, they are disabled during high wanted levels, so they will restart once you lose the wanted level.
- During the chase, whenever Niko is hit, money is shown flying out of his satchel. It doesn't seem to impact the final reward, however.
- Dwayne's backup function is disabled during this mission.