Double or Nothin' Trophy in Grand Theft Auto: San Andreas
Double or Nothin'
Put the maximum bet on red or black and win.
How to unlock Double or Nothin'
In order to play Roulette you must have gained access to the last area of the game: Las Venturas. Roulette can only be played inside casinos which are only located in this area of the game. Las Venturas will unlock once you have completed the mission ‘Flying School’ in the desert. The first casino you will have access to is the Four Dragons Casino when you complete missions for the Triads.
Once you head inside of the casino, the Roulette tables will be in front of you. When you stand near one of the tables the maximum bet for that specific table will appear in the top left corner of the screen. Select a table that has a low maximum bet, e.g. $100 or $1,000. Put the maximum bet on either red or black and hope for the best. You have a 50% chance of winning so just keep trying until you unlock the trophy.
The below video shows the location of the first casino in Las Venturas, as well as how to play Roulette and unlock the trophy: