What tests do you use? How do you employ them, how do you make them interesting? Any suggestions?

I made some gambling rules for one of the chapters of my The Thousand Thrones conversion. Link is in my signature. I can't remember, but perhaps it's chapter 1 ot 2... but it's in one of the chapters.

One of my player's mage is a compulsive gambler, so we end up using this a lot.

We use a normal deck of cards, draw three and show high card, ties broken with next highest card. Sometimes I roll a fortune die to see how many games of winnings that represents (blank 1, hammer 2, boon 3) rather than play out each hand.

You can spend fortune to buy an extra card. You can also make a Skullduggery roll to cheat and draw extra cards equal to the number of successes. Boons/banes determine if you get caught. I'm considering allowing other rolls to influence the game (maybe intuition or guile) in the same way as the cheating roll.

It seems to satisfy everyone, the gambler has won and then lost loads of cash, and no one can steamroller their way to riches with huge die pools.

Ghiaccolo posted gambling rules that we use. I'll post this here and then give our adjustments at the bottom.

Here is my recipe for gambling encounter i've tested yesterday:

Gambling mini-game

Assemble a 7 space progress tracker.
Move each token ahead: a player can choose to advance once up to the number of success / 2 boons scored in this hand. A chaos star put the player back one space....or is caught cheating if they attempted so!

Reapeat 3 to 5 for next hands, until at least one of the players reached the last space (but make sure each one have made an even number of rolls).

At this point the game is over, and each one collect the pot in this manner:

Whoever reached the last space take 1/2 of the pot (if more players reached the last space, you can adjust the portion)
Whoever reached at least the middle space (comprising the player at the last space) shares the remaining pot in equal parts
The others lost theirs moneys.
In case of undivisible numbers, what is not divisible remain on the pot for the next sharing or the next game...

This worked well for me and my players, i hope it wil help someone else too!

The adjustments (aka house rules!):

1. There is a standard buy-in based on the tier of the game. (Can be a 10 silver buy-in, or a 10 gold buy in depending on where you find the game).
2. Difficulty is the contested roll against the best player in the game. So for example, if a master bluffer is using Guile(Fel) 4d, and you are playing the game by 'reading' the opposition Intuition(Int) 3d you're going to be rolling 2 purples. Black dice are added for people cheating, or having relevant skill training.
3. Using the same skill repeatedly makes you predictable. Add a black die for every 2 consecutive turns you use the same skill/stat combination as people get a read on you and your play style.
4. 3 chaos stars means you're caught if you're cheating (for example playing with a parther and using the 'assist action')
5. Comets mean you get some money back (your buy-in) as people buff the pot. Chaos stars mean you've had to bid in further (put in your buy-in again). We usually track these till the game is done.

There are some cards we use to 'buff' as it were. For example 'Big City Bravado' is really useful in having the 'down low' on your opposition, and knowing how the game is played in that section of town.

Hope that helps.

See the Rough Night at Three Feathers thread in GM section, where I explained how I handled "Gambling with Glimbrin".