Casino question

Walk into the casino and spin a single slot machine... Jackpot can be over a million dollars. If he is omniscient he should be able to pick a winner or one close to winning.
If his luck is high enough he could just randomly pick the right one.

 

Casinos are both a gang and a country.
Cookie to those who get the reference

 

Since when is doubling the stakes cheating? Basically that's the only way to win, just that it isn't worth it.
Say you're playing a roulette with min bet 5$ and max bet 500$. You place the bet always on red,and if you lose you double it so when you win you take back the loss + the initial would be win. 5 10 20 40 80 160 320, not many chances there and often there can be even ~15 of the same color numbers in a row which fucks up this strategy, also you need a lot of money and what for, so you can make 60$ an hour and that's assuming you have also enough money for bets of 640, 1280 with you somehow taking another 1~2 seats, if your friends help you with the extra seats due to max bet then you make even less money because you need to share. Anyway even if you do all this and have 5+10+20+40+80+160+320+640+1280$ you still need to wait for at least 5 of the same colored numbers in a row and then keep betting on the opposite color, that with how long it takes for the ball to stop spinning makes it a very slow way of making money.

 

depend in your story modern era,old era,old era there's lot of modern game and old game.

i think kaiji is the best refrence for this one.

 

Getting 400k in 3 days through gambling in casinos is possible and since your protagonist is omniscient, it's to be expected. Problem is, casinos like their profits and they don't like you to win big.

The other posters have already mentioned the risk of winning big, but I'll point out different elements that you should be aware of.

Is your protagonist a first-time gambler or a common face around there? Casinos are more forgiving towards regulars and a regular who have won and lost over the course of a few years will be more likely to be ignored, at least until they reach 100k in winnings than say a man who was never seen there before, is not in their files and suddenly starts winning big. Casinos aren't dumb, they make so much money because they're very aware of those who play their games. A player who has won big and lost big previously would've been recorded and they'll be more forgiving towards the player if he happens to get 400k in a single night.

Who is your protagonist? If it's just a NEET, chances are, he won't even get to 100k winning without being called out by the casino. If the protagonist is something like an oil baron for example, they'll be more magnanimous and allow him to win big a few times because they want him to keep coming back.

Is your protagonist a man or a woman? This may sound sexist, but it is generally believed that women aren't as good as men when it comes to winning big at the tables. While there are many women gamblers who win big, the majority of the big shots are men. So an unknown woman suddenly winning at the tables will be very very suspicious.