The philosophy of adding Gambling element in a game

[doorknob22]

In my game, I want to add a shrine in which the player can pray to the gods, "contribute" 10 gold coins and have a chance to win something (in the game, not real money of any kind).

I'm trying to work out a formula which will balance making this gambling, err, donating, both attractive to the player but not game breaking.
1. Do I go for low chance/high yield or maybe better chance and lower yield?
2. Is there a formula? For example, if each "donation" of 10 gold points has a 10% chance of winning 100 then odds are the player gains nothing. Maybe 10% to win 125 gold? Or 25% to win 30 gold?

Did anyone tackle these questions in their games?

[puppetbomb]

It depends on a few factors:

• Does the number of coins or items bought by coins block the player from advancing the main objective?
• Will it unlock extra content?
• Is it a micro-transaction, a free game or a one-time pay game?

[doorknob22]

1. When you spend money in one point, you could always spend it in another, otherwise there would be no dilemma for the player.
2. The extra gold could be used to purchase new troops, build a fort etc. It can be obtained in other ways but that would take more turns.
3. There is not real money involved in any way, only game money.

My main question is: how do I make in-game gambling interesting and fun without breaking the game.

To clarify: there is no real world money involved, only game money.

[Imperf3kt]

Add unique "prizes" that can only be obtained that way?
Make story specific consequences that depend on gambling habits?

Keep in mind EU, UK and US, etc gambling laws

[DanOrgan]

If this action is required to continue the story and there is no way to avoid it, then the chance to win must always be higher. Otherwise, it is up to your decision.

Keep in mind EU, UK and US, etc gambling laws

Interesting. Could it affect single-player games without actual currency, only with game points? I think it is only for multiplayer games and microtransactions.

[Imperf3kt]

Keep in mind EU, UK and US, etc gambling laws

Interesting. Could it affect single-player games without actual currency, only with game points? I think it is only for multiplayer games and microtransactions.

No, it affects fake gambling too, especially if you're marketing your game to underage people. Look up simulated gambling regulations for a better explanation than I could give.