Summarize:

A lot of the fun of King's cup comes from the "house rules" that have grown around it. Every game is different, and comparing games or playing with new people often leads to new and exciting rule changes. The following steps give 1-2 variations on each card, but you can mix and match them however you want. Aces are generally big rules, and often require the most drinking.   Ace is for race. If a player draws an ace, they must pick another player and race them to the end of their cup. Both players must finish their entire drink.  Ace slap your face. If a player draws an ace, everyone at the table has to slap their face. Last one to do so takes a drink. Two is almost always "you," meaning you point someone out and they must take a drink. But there are some variations.  2 means shuffle. If a player draws a 2, everyone at the table has to switch seats with someone else. Last one seated drinks. In nearly every variation, 3 is me. But you can also use it as a "direction shifter." If a player draws a 3, the direction of play is switched from clockwise to counter-clockwise. Four is sometimes used for "women must drink," thanks to a rhyme with a certain nightly profession.  4 is for dinosaur. If a player draws a 4, they have permission to use a permanent marker to draw a dinosaur on the face of another player. There are a lot of variations on 5, including:   5 is for jive. As soon as someone pulls a 5, everyone must start dancing. The last person to bust a move drinks.  5 is for dive. If a player draws a 5, everyone must dive under the table. Last one to do so must take a drink. Six is often used to mean, "guys must drink," thanks to a rhyming similarity between "six" and some common male slang.  6 is for thumb master. If a player draws a 6, they become thumb master. Every time they put their thumb on the table, all the other players must do so too. The last one drinks. This can happen at any point in the game until someone else draws a 6. Seven is another card with a lot of variety, depending on who you're playing with. Some people make it "thumb master," or "never have I ever," depending on the other rules.   7 is for snake-eyes. If a player draws a 7, they become snake-eyes and anytime they successfully make eye contact with another player, that player must drink.  7 is buzzing. This is a group rule. Moving clockwise, the each player counts up, so the first player says "1," the second says "2." etc. However, you must replace each multiple of seven (14, 21, etc.), or each mention of seven (27, 37) with the word "BUZZ!" Mess up and you drink, and the next card is drawn. Since 8 is so easy to rhyme with other words, this card has a lot of variations.   8 is for the hate. Choose a player, who must start drinking until you say stop. However, if they finish their drink before you say stop, you must play the same game-- but with them in control.  8 is for straight. There are two options for this rule. Either the player sitting directly across from the cardholder must drink or the person holding the 8 must drink a straight shot of any alcoholic beverage that the table deems fit. It must go down "straight," without a mixer or glass of water These cards usually fill up whatever rules you didn't use with the other cards. Some idea include:  Draw again.  Minister of Foreign Affairs. This makes you the only person able to talk to people who are not playing King's Cup at the moment. Sometimes, if things are casual or the drinks varied, you might just skip the King's cup. There is a variety of ways to do this:  King's are table-slave."' If you draw a King, you must now do the bidding of the table, within reason. Usually, this means you refill the drinks and get new ones every time someone runs out, or someone else draws a King. Never treat the table-slave poorly -- you never know if you're next. "'Kings are Categories:'" If a player draws a King they can choose a category, such as "dog breeds" or "types of car". Then each player at the table must name something that fits into that category, such as "poodle" or "Toyota". When a player cannot think of something that fits into the chosen category within 5 seconds, they must take a drink. Some people play with 10 for Categories instead.
Know that you can adapt, bend, and adjust the rules however you want. Change the Ace rules. Change the 2 rules. Change the 3 rules so that it reverses the game direction. Change the 4 rules. Change the 5 rules. Change the 6 rules. Change the 7 rules. Change the 8 rules. Change the 9 and 10 rules. Replace the King's Cup rule to avoid drinking the pot.