Disclaimer: Farm craps is a real live game that I have participated in, not a joke, as much as this might sound.
Farm craps is a good ole boys gambling game played when extremely drunk. It is made for older folks, and basically presents a long period of time when a bunch of country boys can stand in a field and drink, waiting to see who wins.
The game is played in small fenced-in field. Usually in Kentucky, this is a practice track for horses, but any small pen will do. The pen is divided into a grid of about as many squares as you expect to have participants, usually by spray paint (Do not use string! The results are disastrous!). Then each participant plunks down a fixed amount (usually set between $1 and $5) and picks a square. The bookkeeper will note their square in the books (so no one can exchange squares). The pot usually comes out to about $150 dollars.
When everyone has bet, a single farm animal, usually a horse in Kentucky but any large animal will do, is led into the pen. Whoever's square the animal craps into is the winner. Many of the participates will run around attempting to get the animal to come into their square, sometimes by food. But, you are not allowed to touch the animal or enter the field; anyone who does (and somebody always does) is disqualified. If the animal doesn't crap in about 30 minutes, another animal is brought in and so on until a winner is declared.
While waiting for the bet to come in, a lot of drinking goes on. The drink of choice in my neck of the woods is bourbon, but often the participants bring their moonshine. Most of them are at least 40 years old, and there is often a large contingent of drunk middle-aged women who care more about craps game than anyone else there.
Obviously since you are betting on poop, you aren't going to have a lot of strategy, but the best squares are one or two squares away from the fence. The animal will often stand near the fence, and you want the square his crap would land in if he was standing at the fence. That way you can feed him to keep him in that spot, and your food will hopefully make him crap. These squares are taken fast so you have to basically know the guy who's running the game so he'll put you down for the square before it begins.