Diamond Casino Heist: Essential Prep for Vault Keycards and Patrol Routes

Beyond needing to get a level 2 security pass, there's additional general prep missions that we recommend for the Diamond Casino Heist.

This guide focuses on two of the most important: (1) acquiring Vault Keycards for access; and (2) completing Patrol Routes to reveal guard positions on your minimap. While some preps like Duggan Shipments can be skipped for certain approaches, these two are essential for a stealthy and informed infiltration whichever approach you are using for your Diamond Casino heist.

Vault Keycards

There can be two types of mission to acquire the vault keycards.

The first possible mission requires you to hijack a prison bus and get the keycard from one of the guards at the prison while you impersonate a prison guard. Once you head inside the marked tower, you will come across a guard, just take out the guard silently and search his body for the keycards. After you've acquired the keycards, you can leave the prison the same way you came in using the prisoner bus and you are done.

Note that there is a faster way to do this first mission, but it is not safe and we do not recommend doing it this way. You can go directly to the prison in your own vehicle and head to the tower to get the keycard. However, as you enter the premises, the guards are alerted and the snipers in the prison are very strong.

They will annihilate you. Sometimes even one-shot killing you. So if you're not careful and confident about this approach, it is best to play it safe and head in and get the keycard using the prison bus. This method can also work well if you have an Oppressor Mark II but nonetheless the snipers are still very dangerous.

The other mission is fairly simple too, you just need to go to two security guards situated at two different locations, kill them and get the cards. One guard will be drunk on the street while the other will be having "a good time" in a motel room. Just make sure that when you are taking them out, you use a suppressed weapon or kill them using a melee weapon to avoid cops.

Patrol Routes

This is an optional general prep mission, but it is one of the most important. If you complete this mission you will be able to see the enemies or guards on your minimap during the heist. If you don't do it, then the guards will not be visible on your map. It is absolutely necessary that you complete it, so you can easily see where the guards are during the heist, when in stealth mode.

In this mission you need to find a specific car and take a photo of the contents of the trunk. The mission location is always different, but the cars are always the same, so you can never mistake the car for any other once you've identified it. There are two possible cars you can get — it can either be a gray colored car or a black colored car. You can either sneak your way to the car or just kill all the guards and approach the vehicle — it is completely up to you. Just make sure when you are going in killing everyone, not to accidentally blow up the target car!

You can see for this particular location, there is a black car (circled in green) right next to the gray car (circled in red). So when you arrive at this location it can be either one of these. It is applicable for other locations as well, you will always get either a gray colored car or a black colored car. The best part is that the model of these cars will be the exact same in all the locations, so once you've identified it you'll know exactly what you're looking for during your next run.

Completing these prep missions will significantly improve your chances of a smooth and successful heist finale. Just remember that you'll need to acquire the important Level 2 Security Pass for easier access, too.

If you're trying to complete the Silent & Sneaky approach, you first need to complete some approach specific prep missions.