Okay, even though pretty much everyone in the world and their mother knows how to play beer pong, the way I see it, it's such a classic game, it definitely deserves a page of it's own. Enjoy.
You will first need a table, longer than it is wide. Ping pong tables are perfect, or if you've got a long enough piece of plywood and two saw horses, your golden. Kitchen tables work but only if they're very long.
You'll need 11 cups per end of table. So, all together, 21 (ironic, huh?)(doesn't 11x2=22?). Line the cups up in a pyramid, like this:
Your pyramid is pointing at the opposing team on the opposite side of the table. Fill all ten cups up about 1/4 of the way full with your beer of choice.
You'll also need a bucket of ping pong balls. Definitely get more than you think you'll need, because you WILL lose some under cabinets or refrigerators etc.
Fill the remaining 11th cup with water, the ping pong balls WILL hit the floor, you don't want dirty nasty dirt/cat hair/who knows what else covered balls in your beer do you? Wash them off in the water cup before you shoot.
The most basic of all pong rules is:
SINK IT, DRINK IT.
You can play in teams of two or just by yourselves. Essentially the main aim here is to get your ball into your opponent's cup. If you sink it, they must drink the cup of beer you sank your ball into. First team to have all ten cups gone loses.
Eye For Eye
To start the game off, study your opponent's pyramid, quickly! Then, you and your opponent must stare each other in the eye, and shoot. No looking at their pyramid once the eye contact has begun!! essentially it is a blind shot, first team to sink a ball goes first.
Let's say your opponent's team sinks first...
Return their ball back to their end of the table and sit back and watch as they take a shot at your pyramid. If they sink a cup, you must immediately remove that cup from the table and drink the contents. Put the ball in the wash cup, and wait your turn. Once your opponent/s have taken their shots, it is your turn to do the same, so on and so forth, the point is to make the other guy drink all his beer first!
I myself am a beer pong authority figure, I know of many, many ground rules and have played in arenas where the house rules literally cover an entire living room wall. I'm going to list the basic ones, the ones that seem to reoccur whenever I play. Feel free to edit this post with ground rules you think should be here, etc.
While a player is shooting his/her ball, his/her elbows should NEVER be over the table. If your elbow is over the table, depending on the crowd you play with, you may either lose a turn or be forced to take two steps backward.
By shooting a ball directly through the air into one's cup, you are removing one cup from the pyramid. However, if you BOUNCE a ball into your opponent's cup, you may choose one other cup to remove from their pyramid.
If your ball is about to sink into an opponent's cup, but kind of swirls around the rim a bit before sinking, unfortunately it is totally lawful for for your opponent to blow air into the cup and send the ball flying out.
If they manage to blow the ball out of the cup, but by some act of the almighty noodle god the ball sinks BACK DOWN into ANOTHER cup, that constitutes as two cups to be removed.
Distracting your opponent is absolutely lawful in this game. Do something on the side of the table, wave your arms wildly, do a crazy dance, scream just as their about to shoot, ladies take your ta-ta's out, do whatever you want, BUT...
STAY on your side of the table. Do NOT touch the player shooting, and do NOT touch the ball while it is in the air. You immediately lose your team's turns.
The Almighty Trifecta
The Almighty Trifecta is a glorious achievement only ever performed by total accident or by people who do absolutely nothing but play beer pong. The Trifecta happens when three cups are set in a pyramid state. When you have three cups, all lined up in a pyramid, you have a teeeeeeny tiiiiiny window of opportunity to land your ball, RIGHT in between the three cups, balancing it ever so slightly on the rims of said three cups, not sinking any one cup, just balancing perfectly between the three. When this happens, regardless of how many cups are left on the table, the game is over, the team who shot the Trifecta wins, and the opposing team must drink all their remaining beers.
These are the standard House Rules that I personally know of. If you feel like you have another that should be added please feel free to add it.
Optional rules are great for making the game interesting, it's like playing poker with hundred dollar bills as opposed to loose change.
Front Cup Fuck-Up
The front cup fuck-up is a great optional rule if everyone is already drunk, and beer pong is not the main event anymore, it's just sort of happening in the background. Front cup fuck-up happens when an opposing team calls out, "Front cup fuck-up!" and aims for the front cup. If they sink it, same as the Almighty Trifecta, the game is over, the team who sank front cup fuck-up wins, and the opposing team must drink the remaining beer.
Balls back occurs when one team throws a shot that bounces off a cup, and rolls back across the table. Once the ball makes it past the halfway point of the table, the team that threw the original shot must declare "BALLS BACK!" Upon doing so they can then take their ball back, and take another shot. The catch here is that nothing is free, the regained shot must be made with the player's back turned to their opponent's pyramid.
Celebrity Shot takes place in a lot of beer pong games. While two teams are playing beer pong there is undoubtedly an audience cheering on the two teams, shouting advice and yelling inaudibly. Because of this, maybe you're not comfortable taking this next shot. Maybe you want someone else to take it for you? Call out "CELEBRITY SHOT!" and pick an audience member to step up and shoot for you. Be careful who you choose, this can only happen once per team.
Owning the Table
Owning the table isn't so much a shot technique as it is a game technique. It's simple, whichever team wins can own the table. That means that only the losing team can change. The team who owns the table at the end of a game, doesn't move. New team arises, and they then have the opportunity to win the game and own the table.
This is the realm of unacceptable bullshit. Being drunk, doesn't give you a valid excuse to be an asshole. Play by the rules or get out.
Ganking is unacceptable bullshit numero uno. Ganking occurs when a team owns a table, and they walk away from the table for less than 3 minutes. Some inexperienced/stupid players will take this opportunity to "GANK" the owners of the table, taking their spot. This is absolutely illegal in beer pong. The wait time before a table owning team is removed from the game is 3+ minutes. Once the time lapse has exceeded three minutes, the table owners are already disqualified. Ganking is ridiculous and a very easy way to get one's drunk ass beaten.
Water Cups Count
This is total bitchery and should be avoided. Water cups, aka wash cups, DO NOT COUNT for the pyramid. If you sink a wash cup, good job! The ball is clean, your turn is spent, it is the same as a miss.
Wall shots are excellent displays of perfect aim, and algebra. They also do not count for any more than one cup. Some could argue this and say it deserves two, being that it is technically a bounce, but that is open to interpretation. Wall shots are fun to watch, more fun to achieve, but leave you with nothing all that special. UNLESS, you wall shot a Trifecta, in which case a crown materializes on top of your head and "We are the Champions" plays softly in the background.
There are two variations to this unacceptable bullshit.
1. The first is similar to a wall shot, in that it's kind of a cool move if you can pull it off, but it leaves you with nothing. This happens when someone has removed a cup that was sank from their pyramid, is about to drink said cup, and the second teammate from the opposing team sinks his/her ball into the cup afore mentioned player is about to drink. Yes it is tricky, yes it is impressive, but no it does not constitute as a second cup to be removed.
2. The second variation of this unacceptable bullshit is disgusting. Essentially a player puts the ping pong ball in their mouth, and shoots it out with their tongue and air pressure in an attempt to sink a cup that way. This is gross, as someone's spit is now all up in your beer, and totally defeats the purpose of the wash cup.