Is the random chest game riggable?

Solution 1:

If you get the nerdy glasses from a shrine, the true chest is revealed. The only way I have seen that you can get the glasses if you have some sort of vision defect on the character.

Solution 2:

As Renderless said, the Nerdy Glasses will show you the correct chest. However, Calypso's Compass will show you the correct chest, as well.

In addition, there's another way to improve your expected payout with this game. The winning chest will produce coins/sacks/diamonds such that the total base value is triple what you paid. However, if you have any form of "Bounty" effect active (the Bounty effect is the game's term for any effect that increases the value of coins), the money from the winning chest is multiplied, as well! Ex: If you have $1000 when you play, you will lose $250. If you win, then money items totaling $750 base value (1 diamond, 2 bags, and 5 coins) will appear from the chest. If you have a Bounty of 100%, however, then the total value will be $1500.