Card Games/Egyptian Ratscrew
This game is a matter of quick thinking and even quicker reaction time. It's not the type of game you'd play to relax. It is a mix of slapjack and war.
The Rules 
There are many variations, but the basic goal is always the same - get all the cards. People take turns putting down a card, and at certain points, one may slap the pile and get all those cards. Special rules apply when a royal card (J, Q, K, A) is played.
When one person plays a royal, the next person gets a number of "chances" to play a royal themselves. Otherwise the person who played the royal gets the pile. If a royal is played by the second person, the third person gets a number of chances, and so on...
- Ace - 4 chances
- King - 3 chances
- Queen - 2 chances
- Jack - 1 chance (!)
When You Can Slap (in order of commonness) 
- Doubles - two of the same face in a row.
- Sandwich - two of the same face with one card in between.
- 10 - if you see a 10, go for it! The problem with this is when the 10 happens to be your last card. It gets annoying.
- Consecutive - two or three cards that are each one apart. (e.g. 7, 8, 9)
- Double-decker sandwich - two of the same face with two cards in between.
- BLT sandwich - two of the same face with three cards in between.
- Jammy - Three cards of the same suit.
- 412 - A four then a one followed by a two.
- 69/96 - A six and a nine or vice versa.
If you slap at the wrong time, or, for example, you see a double but someone else puts down another card before you slap, you must "burn" one or more cards, and put them in the bottom.
Running Out of Cards 
According to some rules, once you're out of cards, you're permanently out. In others, you can "slap in". The problem with this is that if you have no cards, you can't burn any. So "negative" cards are counted. At a certain point, such as -5 cards, the person is permanently out.
- Remove all rings.
- Cut your fingernails.
- When you put down a card, flip it so the other person sees it before you.
- Don't slap harder than necessary, don't pound with your fist, don't karate chop the pile, etc.
- Don't "hover" your hand close to the pile.
- can't see me
- Instead of flipping toward your opponent, flip to the side.
- Touching the cards because you think they're yours is equivalent slapping them. So when the opponents are at their last chance for a royal, slap right after they put down their last card. If they didn't play a royal, and there was nothing to slap, it's yours anyway. If they didn't play a royal but there was something to slap, you just won a lot of cards. If the opponent did play a royal, there's a 25% chance it was the same as yours, so it might be a double.
- Plan Ahead
- Keep a mental note of whether you have back-to-back face cards in your deck. If you don't, always slap after you have played a face card and the next player has used up his/her chances. Even if your opponent's last card was a face card, you have nothing to lose — you know that your next card (to be burned) is a number card. Note: if you do have back-to-back face cards, then you run the risk of burning a face card.
- Happy Slappy
- If you're desperate (and willing to antagonize other players), slap every single card played. This is especially useful if there are many rules (and thus many chances) or if the burning level is low.