Please, whenever possible, link this post to help out your fellow players.
This is best with 2 players, if possible, to maximize profits.
You'll need an Arcade, here's a list of all of them.
I prefer the Eight Bit Arcade because of its location and accessibility to the Garage, as well as the fact that it makes most preps spawn in the same locations for easier completion of preps.

Here's a list if guides that'll help with getting started with the Diamond Casino Heist:

Scoping Out

Scope Out Guide [Skip to 4:36]
All Access Points
All Points Of Interest / POI

Tip 1:

While doing Casino Heist preps, you can make Lester shut up and show the mission objective faster by giving one of your contacts (Mechanic, Assistant, hell even Brucie) a call, as long as you know the contact you call will pick up the phone and not just leave you ringing.

Tip 2:

[Make sure to call Simeon or Martin and request a job before you start a prep, as you cannot request a job while doing Casino Preps]
In some missions you are unable to call Lester and call the cops off of you. During these missions, you can get the cops off of you for free by calling Simeon or Martin and request a job. Once you get the job, join it.
AS SOON AS YOU JOIN THE JOB, LEAVE AS SOON AS POSSIBLE. If you don't quit, you run the risk of the Host starting the job and therefore cancelling the heist prep.
Once you leave the job, you'll be back in Freemode with no cops on you, and you'll still have your heist prep equipment.

Note:

There are two Access Points that are required for the way I run the heist, in Aggressive and The Big Con (Gruupe Sechs), being the sewer entrance on the right side wall in the first opening, and the tunnel entrance leading into the center of the track.

Scope out the Casino

Look for Artwork and Gold, as they are the best (unless Diamonds are available in the vault. In that case, Diamonds are the best)

Changing vault contents

If you've completed all three approaches (Silent & Sneaky, Aggressive & The Big Con), you'll have unlocked the ability to cancel the Casino Heist by calling Lester. You can use this to cancel the heist if you get Cash, or any Vault Content item you don't want.
If you find the Vault contents and get something you don't want, like Cash, you can call Lester while still in the Casino and cancel the heist. Go back to the Arcade and pay the 25k to start the heist again, and you should have a different item for your Vault Contents.
This will essentially allow you to get a second Vault Content item by trading 25k to start the heist a second time with about 8 minutes of finding and hacking / killing the Casino Security guy and going to the Casino.
If, once again, you get a Vault Content item you don't want, exit the arcade, call Lester & cancel the heist, enter your Arcade, rinse and repeat.

Personally, I cycle between Aggressive and The Big Con (Gruupe Sechs).

Now, because I prefer doing the heist through the Aggressive and The Big Con (Gruupe Sechs) approaches, I have little to no experience doing the Silent & Sneaky approach, and thus will be basing this post off of my personal experience in the other two approaches.
Note I'm not going to go into every single prep mission, mandatory or optional as that would take too much time for me. You can look up the rest of the preps on YouTube or Google. I'm only going over my preferred Gunman, Driver, Hacker, the preps that I prefer to do / prefer not to complete, and how I complete the heist.

Aggressive

Gunman: I prefer Patrick MacReary, 8%. I can't remember the other weapon available, but I know he allows you to choose an LMG with 100 round mags. I prefer to use the LMG. You can unlock by finding him in the back of a police van. Take the van to the objective area by following the yellow marker and you'll unlock him.
Driver: I prefer Karim Denz, 5%, which has decent vehicles. I prefer the Sentinel Classic.
Hacker: I prefer Paige Harris, 9%, which you can unlock by owning a Terrorbyte (which you can unlock by owning a Nightclub).

The preps I prefer to do are:

Unmarked Weapons, Getaway Vehicles, Hacking Device, Thermal Charges, Vault Explosives (I prefer to use a Stromberg while doing this mission), Reinforced Armor, Vault Keycards, Patrol Routes, Duggan Shipments, Security Intel (unlock by owning a penthouse and completing the penthouse missions), and Security Pass.
For the Reinforced Armor, I only do this if I have Gold or Diamonds as it slows you down. I also only do this if I am a low level or if I have low level teammates, because low level = low health. If I have Artwork or Cash I don't do this.
As for the Boring Machine prep, you don't need to have the Boring Machine to access the sewer. All you need to do is have took a picture of it and sent it to Lester during the Scope Out prep.

The Big Con

Gunman: I prefer Karl Abolaji, 5%. He has access to the Mini Uzi (I forget the in-game name) and the double barrel shotgun. I prefer the Mini Uzi. *You're going to be mostly going up to people and meleeing them / knocking them out instead of shooting them, unless you get caught, then you'll be shooting them.
Driver: I prefer Karim Denz, 5%, which has decent vehicles. I prefer the Sentinel Classic.
Hacker: I prefer Paige Harris, 9%, which you can unlock by owning a Terrorbyte (which you can unlock by owning a Nightclub).

The preps I prefer to do are:

Unmarked Weapons, Getaway vehicles, Hacking Device, Entry Disguises (2 preps), Vault Drills, Exit Disguise, Vault Keycards, Patrol Routes, Security Intel, and Security Pass.
I don't do Duggan Shipments as usually use my weapon to melee / knock out the security guards at the Casino, and since a melee is a one hit one kill, regardless of level of armor they're wearing, I don't usually do this mission.
Completing the Yung Ancestor missions allow you to have the Grotti Furia, a supercar, as an extra getaway vehicle, although it spawns in the parking lot which is surrounded by cops. I would not recommend doing this.
Again, 2 players are recommended. Start the Heist, get to the Vault. One of you work on the first main room with the big circle table in the centre while the other one will start hacking whichever doors lead to 2 or 3 Artwork or Gold / Diamond / Cash tables. Always go for the rooms that have more than one cart.
Tip: With Gold / Diamonds, you cannot sprint / run, you can however trot. If you go into First Person and tap / press and hold whatever your sprint / run button is, you'll see your character's weapon / screen shake, indicating that you're trotting. Doing this in First Person is actually faster than Third Person.

There are two was I like to lose the cops

1, through the sewer, and 2, by helicopter (Helicopter Route)
[Disclaimer: This strategy is not recommended if you're trying to get the Elite Challenge, as this will most likely take more than 15 minutes, or however long the given time is.]
Once you are out of the Casino, make it to the road. Drive to the sewer opening by the Casino, and if you don't have a car, just run to said sewer opening.

Note:

If you go back the way you came, or anywhere close to the Casino after you lose the cops, you will gain a wanted level again.
Proceed through the tunnel. You'll find a metal gate that you have to pass under, a small vent on the right side, and another vent on the left.
You'll come across 2 paths. Go up the metal ramp on the left. Proceed all the way down the tunnel and down the escalators and ramp downwards. Cross diagonally over the 2 train tracks into the next tunnel with a dirt floor.
You'll find 2 tunnels, left and right. Take either one. You'll find construction, go straight. After this, you'll see a big room. Go straight, take the immediate right and go up the ramps leading to the opening to the highway. If you dont have a car, get one or two and drive to the Buyer.
​
Links to my other posts, which consist of guides, and other useful things I've found & posted.

KEY:

Silent and Sneaky Aggressive Big Con All approaches

List of all annoying bugs

1: Guards will stop moving during the heist from the beginning. Not as obvious during Big Con and can maybe help you out during Aggressive, but is a massive problem when doing Silent and Sneaky without doing Duggan Shipments, which you don’t need. Highlight is the guy on the stairwell going down.

1. A bug at the beginning where a player is stuck where the Arcade interior is placed, which is underground next to NOOSE Headquarters. You’re gonna have to either kill yourself with Tear Gas given in Bugstars Big Con or just start the heist all again. Happens when you’re On Call.
   
2. Money cap at 3.6 million. If you get over 3.6, the money resets back down to what you would’ve got with 3.6 as your take.
   
3. Player Camera gets locked in the Arcade interior similar to number 2, but your character is already starting the heist itself. You can move it around, but you can’t see what you’re doing. Can bug you so much that you can’t even leave the heist until Job Error appears on the top left side of your screen, happens when you’re On Call.
   
4. The heist disconnects you or the other person, and then it displays on the other person’s screen that you left on purpose. Can really start friendship issues if you don’t clarify what happened. In addition this can also happen after heading out of the mantrap.
   
5. NPCs aiming at you from the beginning of the heist. Can get you detected straight away.
   
6. Spawns everyone by Pixel Pete’s instead of their own arcade. I don’t know if it spawns you at other arcades, so more info is needed.
   
7. The mantrap can sometimes glitch to not open the moment you’re standing within distance of it triggering it to open.
   
8. Get stuck on the cart.
   
9. On the way out, going through the security room, you will find that killing the guy on the left isn’t enough to get out. He will get detected by the other dude looking the other way for some reason. Kill both instead.
   
10. Once you’re on the stairs, if you’ve killed anyone in the basement, guards will spawn and they will see the people you’ve killed and you will be detected. A fix is to use the EMP and stay on the right side to avoid being detected by the guy looking out of the reception box thing, or just to not kill anyone by going left and waiting for the guard to pass.
    
11. A Gruppe Sechs van comes out of the Security Tunnel flattening a guard, alerting the NOOSE guards. Can really mess you up.
    

List of all helpful bugs

1. A bug where you’re given all your weapons when failing to get out of the mantrap and restarting from the checkpoint. More info is needed.
   
2. Gold duplication glitch. Two ways of doing it, one where one person takes one bar from two carts, and another takes one bar from three. They wait for the counter to reach 73-81k then they start taking the gold. The other way is for one person to glitch the first cart, which cannot be taken again, the second cart, the third, the fourth and the fifth, and the second person to take right after. There used to be another way which got you more money overall, but was patched.
   
3. Glitching through the daily vault using first person and aiming and ‘phasing’ through. I recommend only doing this with artwork both sides of the heist (before robbing and after) because cash is just not worth it, and I only recommend to do it with gold after robbing the vault; having an already increased take can mess up the duplication glitch.
   
4. Getting Casino optional preps for free. Requires you to first pay for all optional preps (security pass, patrol routes, power drills, ‘insert approach-specific preps), then starting Duggan Shipments and quitting during the black screen before loading outside. When going back in, it should be done, with or without the Purchased tag over it.
   
5. Glitching through mantrap doors. Need more info.
   
6. Arcade and heist progress reset. It’s much more frequent with heists, where you do a random’s heist, then your own heist is reset. That’s fine, you can recover from that. However, you won’t recover all your arcade, and that means all your rewards are reset where you’ve done all three approaches for the heist. It resets you to a point where you have to start all over again, and no, you’re not recovering all those games you bought, only the Drone and MCT.
   
7. The replay glitch (HOST ONLY) where Player 2 gets the full cut. The host quits the game when the map disappears at the end of the heist, and the other player gets the full take. I recommend only doing this with Big Con, as your take can fluctuate with the other two even if you know what you’re doing. Timed right, both players can keep the full take, according to u/Oppipoika. This can only be done on PC and on 30FPS.
   
8. Big Con Tunnel POI can be accessed from ground. Smashing straight through Lost MC Clubhouse, and smashing through those blue fences at the end. Only recommend doing this if you have Videogeddon Arcade, because it’s much faster taking the recommended way then cutting through the grass instead of making the curve turn.
   
9. Hybrid approach. Go with Bugstars, kill the guard outside the back of the entrance before entering the checkpoint. Should put you in an Armored Van and make you do Gruppe Sechs.
   

Check in everyday for new updates and also comment below for bugs I haven’t encountered yet.

AS OF NOW I WILL NO LONGER BE UPDATING THIS GUIDE
I’ll start by going in order of missions and adding extras as needed by editing the TBA (to be added) as soon as I can review the information
Leave any information you can in the comments fill in and I’ll add it in when I can
——The Scope Out——
Difficulty: Very Easy
Time: About 10 minutes
Description: the player must scope out as many points of interest if the can for the most options
Miscellaneous:
Vallet Security guard Purple keypad Inside (dome) camera Outside (box) camera Vault Blueprints (in mrs bakers office)(requires casino penthouse, or a friend with said penthouse)
Access points:
Ground (3)
Main entrance (west) Waste disposal (north) Staff lobby (east)
Roof terrace (4)
2 doors on the north side 2 doors on the east side
Roof (2)
North helipad South helipad
Underground (2)
Security tunnel (under dirt track) Sewer (the drainage ditch by the casino, there’s an entrance at the beginning of it, head down until you see some metal bars that would lead under the casino)
-important notes-
Once you have discovered every point of interest available in this setup, you won’t be able to do this setup for other heist because all poi’s are now permanently unlocked
——Vault contents ——
Difficulty: Very Easy
Time: about 5 minutes
Description: You are trying to find your target, the valuables you’ll be stealing during the heist To start this setup, you hack a guards phone to get into the casino’s system and then enter the casino to walk around and find a strong enough signal for Lester to hack into the cameras BE SURE YOU FULLY ROTATE ALL 6 CAMERAS TO THE TO UNLOCK THE REST OF THE POI’S, if already unlocked all poi’s just skip to the vault camera.
When scouting out the target it is completely random chance what you will be stealing from the casino
Cash is the basic takes and take a while to grab, but it can still pay about 2.1million Normal and 2.4million Hard total (minus crew cuts)
Paintings have better value and are the quickest to grab, to get them you must cut out the paintings but again this is really fast so you might be able to get a cheaper hacker or spend the extra time grabbing lock boxes, with this take you can make about ??million Normal and 2.7million Hard (minus crew cuts)
Gold has great value, it takes time to grab just like cash but is also a lot heavier, this means you can no longer jump but the reward is worth it because it can pay about ??million Normal and 2.8million Hard (minus crew cuts)
There’s also a glitch to get a lot more gold off one tray so abuse it before it gets patched
Diamonds have the greatest value and have just been officially added to the loot pool, you grab trays of diamonds like you would cash or gold and they are worth about ??million Normal and ??million Hard (minus crew cuts)
———Crew members and Characters———
These are free mode missions and secrets that can affect the casino heist by giving access to new characters and crew
There is also the standard crew for comparison
——Optional Characters——
Yung Ancestor
Difficulty: Very Easy
Time: 2 minutes
Effect: adds another route to “The Big Con” Description: Head to the casino and go up to the roof terrace to enter a cutscene with the celebrity, afterwards Lester will contact him to ask if he would like to be involved with the job, a few minutes later you will get a call from Yung Ancestor saying he will help but needs a few favors to trust you
Find the rest of this missions details at the “Setups” section
——Hackers——
—Rickie Lukens—
Cut: 3%
Skill: Poor
Requirements: None
Vault time when undetected: TBA
Vault time when detected: about 1 minute 30 seconds
Notes: Please do not even consider using rickie
—Yohan Blair—
Cut: 5%
Skill: Good
Requirements: None
Vault time when undetected: TBA
Vault time when detected: TBA
Notes: TBA
—Christian Feltz—
Cut: 7%
Skill: Good
Requirements: None
Vault time when undetected: TBA
Vault time when detected: TBA
Notes: Use this character if you don’t have access to the next two
—Paige (Unlockable)—
Cut: 9%
Skill: Expert
Requirements: own a terrorbyte
Vault time when undetected: TBA
Vault time when detected: TBA
Notes: this is the best character to use since she is slightly cheaper then Avi
—Avi (Unlockable)—
Cut: 10%
Skill: Expert +
Requirements: “Destroy Signal Jammers” Free mode mission
Difficulty: Easy
Time: 20-40 minutes
Description: destroy all 50 signal jammers hidden across San Andreas for money and Avi’s services (guides available on YouTube)
Vault time when undetected: TBA
Vault time when detected: TBA
Notes: This character is great but if you have Paige use her since she’s slightly cheaper, the difference in time is minuscule
——Drivers——
(Unknown: unlockable) TBA this character has not been found yet
—Karim—
Cut: 5%
Skill: TBA
Requirements: None
Vehicle selection:
Sentinel Classic (best choice)
Weeni Issi Classic
Asbo (worst choice)
Kanjo
Notes: This driver is the best to pick, they always leave the cars as close to the staff lobby as they can
—TBA—
Cut: TBA
Skill: TBA
Requirements: None
Vehicle selection: TBA
Notes: TBA
—TBA—
Cut: TBA
Skill: TBA
Requirements: None
Vehicle selection: TBA
Notes: TBA
—Chester McCoy—
Cut: 10%
Skill: Expert
Requirements: None
Vehicle selection:
Vagrant
Everon
Zhaba
Outlaw
Notes: TBA
——Gunners——
—Karl Abolaji—
Cut: 5%
Skill: Poor
Requirements: None
Weapon selection:
TBA
Smg and molotovs (aggressive)
Micro smg (Big Con)
Double barrel shotgun (Big Con)
Notes: TBA
—Charlie Reed—
Cut: 7%
Skill: Good
Requirements: None
Weapon selection:
TBA
Machine Pistol (Big Con)
Sweeper Shotgun (Big Con)
Notes: TBA
—Patrick “Packie” McReary (unlockable)—
Cut: 8%
Skill: Expert
Weapon selection:
TBA
Compact rifle (Big con)
Sawed off shotgun (Big con)
Combat MG MKII (Aggressive)
Difficulty: Easy-Medium
Time: Random Chance
Requirements: “Rescue Patrick” Free mode mission
Description: find a police van blaring it’s siren driving around Los Santos and Blaine county, when close enough a blue arrow will appear over the van and a blue dot will show up on your map indicating the vans location, by getting even closer Packie will ask you to help him and another person to “give us a hand?” The implication here is he wants you to steal the van and drive it
the way to go about this is just to shoot the van enough and it will eventually stop, allowing you to steal it and bring it to Packie’s safe house at Vespucci beach,
Notes: there is a 5 minute time limit that begins when you enter the van
Packie has the best weapon selection in aggressive but this does not outweigh how much he cost this is player choice
—Gustavo Mota—
Cut: 9%
Skill: Expert
Requirements: None
Weapon selection:
Carbine rifle (Big Con)
Assault shotgun (Big Con)
Notes: TBA
—Chester McCoy—
Cut: 10%
Skill: Expert
Requirements: None
Weapon selection:
TBA
SMG MKII (Big Con)
Bullpup Rifle MKII (Big Con)
Notes: not recommended because of cost
——Approaches——
It’s recommended to have 3 or 4 players for the best take
—SILENT AND SNEAKY—
Stealth difficulty: Hard
Loud Difficulty: Medium-Hard
Time: 15-20 minutes (minus restarts)
Description: Silent and sneaky is one of the stealth approaches, you go inside with tactical gear, night vision, suppressed weapons, tasers, and an emp bomb (if the setup is complete) that the host can activate (explained below) This hiest allows you to slip in undetected and you can still slip out undetected.
-Things to note-
When you enter the vault you will have a certain amount of time depending on your hacker and whether or not you are detected by the time you arrive to the vault, if you fail to leave the vault before the timer hits “0” gas will fill the vault and the alarm will trigger
Guards will be alerted to the following: seeing you, shooting a guard without a headshot (they yell), killing a guard next to another, a dead body, a bullet flying past them, a bullet hitting a wall, a guard watching you destroy a camera, and hearing unsuppressed gunfire
The casino will raise the alarm for the following: a guard being alerted, a camera spotting you, a camera spotting a dead body destroying more then one camera, and not leaving the vault before the clock hits “0”
Guards are oblivious to the following: getting a headshot or stealth melee even if the guard yells, destroyed cameras, the sound of broken glass, and the sight of broken glass
You can disable cameras with the taser, but they will come back online, you can also shoot and destroy one camera but destroy any more and the alarm will sound
If the host completed the EMP setup, they will have access to a phone app named “Detonate EMP” this will set off the EMP of course knocking out all electricity for about 1-2 minutes, this includes: cameras, locked doors, elevators, and lights (this will make guards have a really small cone of vision)
-Important notes-
Triggering the EMP does not raise the alarm (credit goes to u/Aleapp2556 for discovering this)
Not breaking stealth until outside will give an award
You can restart the heist at anytime by running out of lives
-Best plan of attack-
Enter the south helipad
Exit the staff lobby
High level buyer
Decoy driver (optional, lowers how many stars you have)
-Steps-
Enter the cargobob
Parachute to the casino
Rappel down the elevator shaft
(You are now in the staff lobby)
Take out everyone quietly
Proceed to elevator
(You are now at vault security)
Take out the remaining guards quietly
Enter the mantrap
Drill open the vault
(You are now in the vault and the timer has started)
Grab as much loot as possible, Dedicate one person to hacking
Leave before the timer ends
Exit the mantrap
Take the elevator or stairs up
(Alarm is now raised, but you are still undetected)
Take out the remaining guards and exit through the staff lobby
Get in the getaway car
Race to Paleto Bay
Escape the cops
Finish the heist
-Overall-
the hiest is slow and very difficult so this may not be the best option for grinding
—AGGRESSIVE—
Difficulty: Medium
Time: 8-11 minutes (minus restarts)
Aggressive is loud and violent, you shoot your way to the vault, blow it open, melt open the gates and steal the loot
-Things to note-
This heist is extremely fast compared to the other two approaches, it can be and has been done in under 9 minutes with high level buyers
there are no drills or hack in the vault itself, just explosives and thermal charges
You can restart the heist at anytime by running out of lives
-Best plan of attack-
Enter sewer(you blow a hole right into the security-room just before the mantrap leading to the vault)
Exit staff lobby
High level buyers
Gunner decoy (optional, but lowers your stars)
-Steps-
Blow into the vault security room from the sewers
(You are now in the vault security room)
Enter the man trap
Blow open the vault
(You are now in the vault)
Set off a thermal before you start grabbing and try to just get everything you can
Exit the vault
Exit the mantrap
Go to the staff lobby via elevator
Exit staff lobby
(At this point stealth no longer matters)
Enter getaway cars
Race to paleto bay
Escape police
Finish heist
-Overall-
this heist is fast and effective and I recommend cycling between both this and the big con
—THE BIG CON—
Stealth Difficulty: Easy or Medium-Hard (depends on route)
Loud difficultly: Hard
Time: 10-13 minutes (minus restarts)
The Big Con is the another stealth approach, but it’s less stealth and more lies and deceit, you use disguises to get your way into the casino with all your tools and equipment needed for the job
-Important things to note-
You only have a ceramic pistol unless you pick up your stashed weapons, but if you pick up those weapons you can no longer pass through metal detectors
Your weapons are not suppressed
Gruppe sechs can get inside the vault no problem
You unlock the ceramic pistol after you are done HOSTING The Big Con
Not breaking disguise until outside will give an award
You can restart the heist at anytime by running out of lives
-Best plan of attack-
Enter Gruppe sechs disguises
Exit noose disguises
Enter security tunnel
Exit staff lobby
High level buyer
Gunner decoy (lowers stars, only helpful if you are actually caught)
-steps-
Enter the security tunnel as gruppe sechs
Park the van
Get into the elevator
(You are now in the vault security room)
Walk on by the guards
Enter the man trap
A lone guard lets you into the vault, you knock him out
(You are now in the vault)
Grab the loot, mind the hacking, one mess up and the alarm goes off
Exit the vault
exit the mantrap
Take the stairs
(Alarm is raised but no one knows where you are)
Take the route to the laundry room
Change outfits
Exit staff lobby NOT MAIN ENTRANCE
(At this point stealth no longer matters)
Get to getaway vehicles
Race to paleto bay
Escape cops
Finish heist
-Overall-
this heist is very clean and quick if you do it right, id recommend doing this and aggressive if you really want to grind it
——About undetected——
When you sneak into the vault undetected you gain bonus time to grab even more loot then you would if the alarm was raised, failure to leave the vault before the gas is released will raise the alarm;
but you still received the bonus time to grab the loot anyhow, so it’s all up to you to either get the extra few lootables or make a clean getaway
——Hard Mode——
Hard mode (just like in normal heist) gives bigger cut with less lives, but this also buffs the security of the place
The way you access hard mode is by playing through a heist (we’ll say aggressive) and then the next (the big con), after playing aggressive it will become locked and unplayable so you have to pick another approach like big con, after that heist is done aggressive will unlock but it will still be “too hot” this is hard mode and will give a bigger cut for a harder heist that’s why it’s best to cycle between both aggressive and big con
——Heist crew——
For the best take each time you need to select the perfect members for the job
-Gunner-
Cheapest gunner all the way avoid shotguns
-Drivers-
If you want more money chose the cheapest driver and pick the sentinel classic, but if you want the trade prices for all the new vehicles you’ll need to use them during a heist
-Hacker-
Now unlike the other two, an expensive hacker is necessary for this job, this person will provide you with more time in the vault, this is where Paige and Avi come in handy
——Setups——
Setups are needed to find the materials necessary to pull off this job, some are mandatory and you cannot start the job with out them, some are optional and can be avoided but also can be the difference between dealing with a few enemies or a few mini-juggernauts
-Weapons-  Need: Mandatory
Difficulty: Easy
Time: 5-8 minutes
Description: The player needs to steal untraceable weapons for the job, a pistol, a main weapon, and a piece of equipment depending on the approach
-Getaway vehicles-
Need: Mandatory
Difficulty: Easy
Time: 3-8 minutes
Description: The player needs to steal 2 vehicles that have just been imported into the US and bring them back to the arcade, if the cars are badly damaged you will have to pay a small fee to repair then on delivery
Important notes
The vehicles can be upgraded with
Level 1: bulletproof tires 10k (recommended)
Level 2: max brakes and transmission and level 1 upgrades 15k
Level 3: turbo and max engine plus level 1&2 upgrades 25k
-Hacking device-
Need: Mandatory
Difficulty: Easy
Time: 5 minutes
Description: the player(s) go to a location being investigated by the FIB, the player(s) need to kill the FIB agents
Important notes
You can be in a guards vision but not for too long
Once you have the device and take the elevator down the guards will begin to shoot you
-Vault key cards-
Need: Mandatory
Difficulty: Easy
Time: 3-7 minutes
Description: the player(s) need to go to 2 separate locations and knock out or kill two security guards on their time off to steal their key cards
-Patrol routes-
Need: Optional
Usefulness for Sneaky and Silent: Needed
Usefulness for Aggressive: not necessary
Usefulness for The Big Con: Helpful
Difficulty: Easy
Time: 2-5 minutes
Description: the player(s) need to go to a parking lot where security guards have gathered, the player(s) will be looking for a car with a certain license plate that Lester will send, Once the player(s) find the car, they will need to open the trunk, take a picture, and send it to Lester
Important notes
This mission can be done by stealth
The car is always a black or light brown Falon GT convertible
-Dugan shipments-
Need: Optional
Usefulness for all heist: Absolutely Required
Difficulty: Medium
Time: less then 10 minutes
Description: The player(s) go around all of San Andreas to destroy 10 security shipments for the casino’s guards (this includes vans, boats, and helicopters)
Effect: for every couple of shipment destroyed, the guards armor will become weaker
No shipments destroy: every guard will have the health of a Cliffford Cyborg juggernaut
7 shipments destroyed: Health of a NOOSE squad member
10 shipments destroyed: Heath of a cop with body armor (3 Star wanted level officer)
Important notes
It is recommended to have 2 players in weaponized vehicles to destroy all the shipments
-Security Intel-
Need: Optional
Usefulness for Sneaky and Silent: Needed
Usefulness for Aggressive: not necessary
Usefulness for The Big Con: Helpful
Difficulty: N/A
Time: N/A
Description: The player needs to own a casino penthouse and do all casino missions for mrs baker
Effect: allows players to know the locations and vision of all cameras in the casino
Important notes
Once this setup is completed once it will be completed permanently
-Power drills-
Need: optional
Usefulness for all heist: Player’s choice but not necessary
Difficulty: Easy
Time: 5-8 minutes
Description: the player must steal power drills from a construction site by stealing a van and delivering it to the arcade
Effect: Gives the ability to drill open safety deposit boxes for a little bonus money (does not outweigh the main target in value)
Important notes
These missions can be completed by using non lethal tactics
-Security key cards-
Need: optional
Usefulness for all heist: absolutely required
Difficulty: Easy
Time: 5-8 minutes
Description: the player must steal a security key card from a casino staff member
Effect Card Level 1: has the ability to give you access to few doors and access points, but nothing else in the higher security areas, those points will need to be hacked
Effect Card Level 2: gives player full access to all casino doors and elevators other then those in the vault
(A level 2 keycard is highly recommend and should be used in every single heist)
——Approach specific setups——
Some setups are specific to certain approaches and can be mandatory or optional
—Silent and Sneaky Setups—
-Vault Laser Drills-
Need: Mandatory
Difficulty: TBA
Time: TBA
Description: the player(s) need to steal 2 military grade laser drills to drill open the vault door
-TBA-
-TBA-
-EMP-
Need: optional
Usefulness: helpful
The player uses a cargo bob to carefully steal a EMP bomb and deliver it to the power station just across the road from the casino
Effect: give the host the ability to call the EMP to detonate it, this will shut down all electronics and lights for 1-2minutes, this mean cameras, locked doors, and metal detectors will be shut off during this time, and since the lights are off the guards have limited visibility, about 1 foot of vision in front of them
Important notes
Triggering the EMP does not raise the alarm (credit goes to u/Aleapp2556 for discovering this)
—Aggressive Setups—
-Vault explosives-
Need: Mandatory
Difficulty: Easy-Medium
Time: 8-18 minutes
Description: the player(s) must travel to a part of the ocean to steal explosives from an underwater mining operation to blow open the vault door
-Thermal Charges-
Need: Mandatory
Difficulty: Easy-Medium
Time: 8-16 minutes
Description: the player(s) must steal thermal charges to melt open the gates inside the vault
-Reinforced armor-
Need: Optional
Usefulness: helpful
Difficulty: Easy-Medium
Time: TBA
Description: The player(s) steals a few sets of experimental armor from a faction to use in the heist as an option of clothing
Effect: unlocks the armor set to be used during the casino heist, the armor is like hiest heavy combat armor when used during the casino heist giving the players more Health but less Speed
-Boaring machine-
Need: Optional
Usefulness: TBA
Difficulty: Easy
Time: TBA
Description: The player steals a drilling machine from a driver hauling the machine
Effect: TBA
—The Big Con Setups—
-Drills-
-Disguises-
-TBA-
——Phase 1 equipment——
On the phase 1 planning board you can buy equipment for finding points of interest or practice on mini-game type puzzle you need to complete while going to or when you reach the vault, you can buy equipment such as:
a model of the casino for $130,000 (Which shows points of interest)
A replica of the casinos security system for $425,000 (for practice with hacking)
And a replica vault door for $900,000 (for practice with drilling)
By taking photos of the security system and vault blueprints in the casino you unlock the option to buy the security system and vault door for practice
Once the equipment is purchased, it will stay permanently in your arcades basement
In order to practice you will need the vault drills (explosives do not count) and/or the hacking device
These items will need to be sourced each time you start a new heist if you wish to practice
My personal recommendation is to avoid this equipment as it’s price greatly outweighs its purpose, since everything can be learn relatively easy during the actual run
——Hacking——
Here’s a quick guide on the hacking during the casino heist
First it should be noted that failing or aborting a hack while undetected will trigger the alarm
There are two types of hacking
Hack 1: Memory
A 6x6 panel of dots will randomize in a pattern of 6 dots going left to right, the player’s job is to memorize this pattern and recreate it to pass the hack, they player may need to do this several times
These hacks have been found really difficult and can be skipped entirely by having a level 2 keycard
Hack 2: finger print
The player is presented with a full image of a finger print and 8 fragmented images of a finger print, all the player must do is select 4 of the 8 fragments that match the full finger print and run the scan
This isn’t as hard as the memory hack, but this can waste time, so be quick but be sure in your decision
A tip for this is to go ahead and match the obvious ones and then study the smaller details of a fragment to try to find it on the full image
——Bugs, Exploits, and other Glitches——
PATCHED If the player leaves the session before finishing “Vault contents” the player can replay the setup for a chance at a better target such as paintings and gold instead of cash
During the heist, a police maverick will spawn on the roof of a nearby police station, the players can grab it before it takes off, but once it’s gone from the helipad it won’t respawn during the same heist even after a quick restart
PATCHED The player can duplicate the gold bar on a tray by leaving a single bar and leaving the tray, start collecting the tray again to spawn a new set of bars

I have just started to do the casino heist prep on both of my characters. On my secondary (which I started doing prep first) I have all POI and a check mark to indicate as much on the heist prep board. However, there is no check mark for the access points.
I have taken pictures of every location and double checked via online tutorials to make sure I did, indeed, get them all.
Main entrance, 2 side, 4 terrace, 2 roof, Security tunnel, Sewer tunnel
That being said, still no check mark on the board. I have replayed the mission multiple times, taken the photos and nothing gives the prompt to send to Lester, leading me to believe I have already done so.
With my main character, during my first attempt at doing this I got the "Scoped Out" award and 800 RP as well as the check mark.
Is it possible that because I didn't get them all on the first attempt and moved onto the next prep mission that I'm not getting credit for the ones I went back and took pictures of?
Any confirmation would be appreciated. I cannot seem to find anyone having this specific issue with the access points.
(Updated: I'm doing the heist for a second time, still no check mark).

Hi everyone, hope you're doing well
I'm currently doing setup for the new casino heist. Scoped out all the access points but still have a few POIs left. Googled them and looks like they're all seen through the camera you hack. Problem is, when I go to scope out the casino as soon as I get there it says "Leave the area." And I can't scope out the rest of the POIs
What should I do? How important are these POIS?

Copied and pasted from my notes. Will update post if needed.
(Silent & Sneaky)
Any Poor Gunman, your preference. Karim. Paige.
(The Big Con) Any Poor Gunman, your preference. Karim. Paige.
(Aggresive) Packie. Karim. Paige.
This is best with 4 players, if available.
You'll need an Arcade. Here's a list of all of them:
Pixel Pete’s [Cheapest] Cost: $1,235,000 Location: Paleto Bay
Wonderama Location: Grapeseed Cost: $1,565,000
Videogeddon Location: La Mesa Cost: $1,875,000
Warehouse Location: Davis Cost: $2,135,000
Eight Bit [Most Expensive] Location: Vinewood Cost: $2,530,000
Here's a list if guides that'll help with getting started with the Diamond Casino Heist:
=Scoping Out= Scope Out Guide [Skip to 4:36] https://youtu.be/Bl8RtQ4mZ8A
All Access Points: https://youtu.be/Om3B42f9qOg
All Points Of Interest / POI: https://youtu.be/C7PAwki06dY
How to replay Scope Out mission: Go to your Arcade. Go to the board where you started the Scope Out mission. At the very top of the board, hover over and select the Scope Out mission, restarting it. You can see the available controls on the bottom right of the screen.
Now, how do you get from around $2,000,000 to $5,000,000 in one Heist?
• Scope out the Casino
• Look for Artwork, which is the easiest, but Cash randgold is okay, too.
• Choose Silent & Sneaky. All prep missions with the yellow square and black marking are Mandatory, you need to do them before you do the Heist. The rest are completely Optional, but will aid you in one way or another.
• Again, 4 players are recommended. Start the Heist, get to the Vault. 2 players will stay in the room you first encounter when you walk into the Vault with the carts, the other 2 will begin hacking any 2 doors. This link will help with the Fingerprint Scanner: https://www.reddit.com/gtaonline/comments/eb0msy/ive_created_a_small_guide_to_help_with_the_finge?utm_medium=android_app&utm_source=share
Tip: With Gold, you cannot sprint / run, you can however trot. If you go into First Person and tap / press and hold whatever your sprint / run button is, you'll see your character's weapon / screen shake, indicating that you're trotting. Doing this in First Person is indeed faster than Third Person.
• THIS PART IS VERY, VERY IMPORTANT. PAY CLOSE ATTENTION. [Disclaimer: This strategy is not recommended if you're trying to get the Elite Challenge, as this will most likely take more than 15 minutes, or however long the given time is.]
With the Gold while playing Silent & Sneaky, there is a glitch. You interact with a cart of Gold, and collect all but 1 piece of Gold [once you get to 3 pieces, take it slow]. Once there is one piece remaining, cancel interacting with the cart. Wait 2-5 seconds, and the Gold will refresh. Continue interacting with the cart of Gold and spam to your heart's desire.
By the time you and the other player are done with the glitch, the other 2 players will be done hacking 1, maybe 2 doors, and will be doing the same glitch as you. There will be about 1 minute remaining. Dont sweat it if there's more or less time. Player 1 & 2, exit the Vault. Once there is 15 seconds remaining, player 3 & 4 will run for the door of the Vault.
Once all 4 of you are out of the Casino, make it to the road. If possible, get a 4 seater car, not a truck or van, and drive to the sewer opening by the Casino, if not, just run to said sewer opening. Run far into the sewer. If you go back the way you came once you lose the cops, you will gain 4 or more stars again.
You'll pass a vent on the right, a broken wall on the right, a vent on the left, metal roofing on 2 portions of the roof of the tunnel. You'll find a metal gate that you have to pass under (which is why you'll need a low vehicle), a small vent on the right side, another vent on the left, another metal gate that you'll pass under. Once you reach this, go straight down the tunnel.
You'll see another vent on the right, and some more metal roofing on the roof of the tunnel. You'll come across 2 paths, one which is a dead end on the right, and one which has a metal ramp and stairs going left, take the metal ramp. Proceed all the way down the tunnel and down the escalators and ramp downwards. Cross diagonally over the 2 train tracks into the next tunnel.
You'll find 2 tunnels, left and right. Take either one. You'll find construction, go straight. After this, you'll see a big room, take the immediate right and go up the ramps leading to the opening to the highway. If you dont have a car, get one or two and drive to the Buyer.

I have just started to do the casino heist prep on both of my characters. On my secondary (which I started doing prep first) I have all POI and a check mark to indicate as much on the heist prep board. However, there is no check mark for the access points.
I have taken pictures of every location and dpuble checked via online tutorials to make sure I did, indeed, get them all.
Main entrance 2 side 4 terrace 2 roof Security tunnel Sewer tunnel
That being said, still no check mark on the board. I have replayed the mission multiple times, taken the photos and nothing gives the prompt to send to Lester, leading me to believe I have already done so.
With my main character, during my first attempt at doing this I got the "Scoped Out" award and 800 RP as well as the check mark.
Is it possible that because I didn't get them all on the first attempt and moved onto the next prep mission that I'm not getting credit for the ones I went back and took pictures of?
Any confirmation would be appreciated. I cannot seem to find anyone having this specific issue with the access points.

I got problems with casino vault poi. on heist board on "to do" list scope out casino and scope vault content are checked both. In "Optional" section "scope all poi" is unckecked and "scope all access points" checked. in vault content scoping i missed some poi i got 7 small pics on the board. i saw on yt videos there are 10 pics there so i missed 3. i wanted to rescan for the remaining poi but can not start that mission at all. circle around it is black and there's no option to start the mission again. circle around "scoping casino" is red and i can start the mission. when i start it and when i get to the casino i immediately get msg leave area just as i approach it. So it seems i found all access points from scoping the casino. When i browse through access points scoped pics (6 pics on the board) circle on some are red and on some are black which means i can pick the ones with red circle and can not pick the ones with black circle. Is that related to the fact i did not find all vault poi scoped on the 1st try so i can not use that entrance for a heist? Can i rescan the vault content for the remaining poi or it's just one time job? am i missing something? is this bug or it's how things should happen? How important for different heist approach is if some vault content are missing?