In the game of Buffalo, players are punished for drinking out of their dominant hand. In all variations, fellow players call "Buffalo!" on the perpetrator immediately upon breaking this rule, at which point he/she must immediately imbibe the entire drink.

 All players are obligated to play for life. There are no exceptions.

The rules are fairly simple, though widely varying, and involve which hand you may use to drink. One version (the natural version) of how to play the game is as follows:

Under no circumstances may any player drink an alcoholic beverage with their dominant hand. Should they do this, any fellow player may loudly say the word Buffalo!, resulting in the perpetrator being forced to immediately imbibe said beverage.

Once you begin playing Buffalo, you are playing it for the rest of your life.

There exist many variations of the rules.

=University of Pennsylvania Version=

A more complex and involved version was created in order to enhance the difficulty of the game. All the rules from the "natural" variation are in place, with the following major change:

*At no point may one's dominant hand grab, hold, or in any way directly touch their alcoholic beverage.*

This rule not only makes the game much more challenging (and consequently results in more frequent calls of "Buffalo"), but also gives rise to many complex and esoteric situations.

=Rules=

* Handles: If an individual touches, holds, or grabs a large container of a strong liquor, that individual has two choices once Buffalo has been called: - The buffalo-ee may elect to take 3 consecutive shots of the liquor. It is important that all three shots be taken back to back without any liquids serving as a buffer between shots. - The buffalo-ee may elect to finish what is left in the container. This option is only applicable when the amount in the container is less than three shots worth.

* Kegs: If an individual touches a keg, pump, or hose, he/she will be forced to start/finish pouring, and proceed to immediately consume the full cup of beer.

* Drinking Games: The rules of buffalo persist into any and all drinking games. Interesting combinations arise with Kings and other rule-based games in which a buffalo-er may create a rule stipulating that all players hold their drinks in the dominant hand, eliciting multiple immediate buffalos. This is generally frowned upon as poor etiquette.

* Non-Alcoholic: If buffalo is called on a beverage which contains no alcohol, careful discretion amongst all players is necessary. Should the drink be touched in a ''reasonable setting'', such as a bar or night club, no player will be required to imbibe their drinks. If the setting is deemed inappropriate, the buffalo-er may be required to imbibe his/her drink.

* False Buffalos: Similar to the false buffalo rule in the natural variation, with the added requirement that the false buffalo-er purchase a drink to imbibe if he/she does not currently have one. Friendly buffalo-ees may elect to transfer their drink to the unfortunate buffalo-er.

* Lefties: It is very difficult to know the hand dominance of an unfamiliar individual. Thus, should buffalo be called on a left-handed player, discretion may be used to avoid a ''false buffalo''. If the incorrect buffalo is the result of mere forgetfulness or inattention, the false buffalo will stand. If no player in the immediate vicinity has knowledge of the player's hand preference, the parties may agree to drop any drinking requirements for one time only.

* Non-Purchased Drinks: May apply to (1) drinks purchased by other consumers in a drinking atmosphere or (2) drinks on sale in a liquor, beer, or wine distributor. The following rules apply in each respective situation: - At no point may a buffalo player 'claim' a stranger's drink by purposefully placing his dominant hand on it and waiting for a buffalo call. Should this happen, intentional or not, the buffalo-ee will be required to finish his own drink, or purchase a new one in its place. - It is generally frowned upon to call buffalo on the future drink purchaser. If he/she is buying alcohol for other players, etiquette stipulates that the potential buffalo be forgiven. If the purchaser is buying a small vial for him/herself, the buffalo-ee may be required to imbibe after its purchase, or substitute a similar owned drink in its place.

* Saves: A buffalo-ee may be 'saved' by another player at any point. Typically, this is only invoked when the player has already had a large amount of alcohol, and other guests wish to mitigate the possibility of danger and/or harm to the player. The saver must make his/her decision immediately, and may do so only if the majority of players agree with the decision.

* Agreement to Play: By calling buffalo on another player, the buffalo-er agrees to have entered into the buffalo contract. Namely, this means the player is obliged to play for life. Under no circumstances may a player call buffalo and later profess to 'not be playing the game'.

=Exemptions=

* Conveyance: Individuals who carry boxes, bags, or other large containers of multiple alcoholic beverages are exempt from the rules of buffalo. If, however, upon removing the individual containers from the large holder, the player violates buffalo, all normal rules apply.

* Requested Immunity: At any point in time, ''before'' touching a drink with his/her dominant hand, a player may request immunity from the other players. Reasonable excuses include eminent activities requiring sobriety, such as tests, interviews, jobs, and so forth. If the player requests immunity ''after'' buffalo has been called, the buffalo-ee must choose a future date within approximately 7 days of the current date to consume the beverage. This is known as a 'delayed buffalo'.

* Facilitating Accessories: Typically called the 'straw rule'. If a player touches a device intended to facilitate drinking (such as a straw or beer bong) with the dominant hand in the process of drinking, he/she is exempt from the rule of buffalo.