As any Texas cook will tell you, a chili contest is serious business. You don't just grab a bunch of people, tell them to cook up a batch of their best and call it a cook-off. There are rules for these things.
How many rules depends on the seriousness of the event, of course, but in almost all cases you'll find at least a handful of basic rules, regulations and guidelines, like those spelled out by the International Chili Society (ICS), including:
While your three-bean chili might deeply impress the neighbors, don't bring it to an official ICS chili cook-off. There are, according to the ICS, only two kinds of chili, and neither contains beans. Red chili is made with meat, red chili peppers, spices and sauce ingredients; green chili is the same except it has green chili peppers instead of red.
While cook-offs typically allow for pre-mixing of spices and the use of pre-cooked, canned tomatoes, competition chili is not pre-made. Ingredients must be combined on-site, and meat may not be pre-cooked in any way.
All cooks should have the same amount of time to prepare their entries. Contestants should start cooking at the same time, with a set number of hours to finish before judging starts. The ICS allows three to four hours, for reference.
Contestants should be informed beforehand how much chili they will need to prepare specifically for the judges -- you don't want to run out come official-tasting time!
Entries should be anonymous to prevent any bias (or perceived bias) in judging. In most cook-offs, each entry is assigned a number that appears on the official judging sheet.
Judging, of course, is the crux of the event, and as such, has its own set of regulations, not the least of which is a standardized set of criteria that determines what makes a great chili.