You typically play with two standard decks without Jokers (104 cards) and from 4 to 6 people. The basic elements of the game are sets and runs.
Sets are 3-of-a-kind or more. For example, three or more Jacks (of any suit) would be a set.
Runs are strait flushes of 4 or more cards. For example, 8 9 10 and Jack of the same suit would be a run.
Aces are wild and may be substituted anywhere in a set or run to fill it in. However, a set or run may not consist *only* of aces. Also, Aces may not be placed below a 2 or above a King in a run.
The game is divided into 7 "hands", each of which requires a different combination of sets and runs to "lay down".
S = Set, R = Run
1st hand: S S
2nd hand: S R
3rd hand: R R
4th hand: S S S
5th hand: S S R
6th hand: S R R
7th hand: R R R
The 1st thru 6th hands run like this:
The dealer shuffles the full deck and deals out 11 cards to every player then leaves the rest of the deck in the center of the table face-down. Once everyone has gathered their cards and is ready, the dealer takes the top card from the deck and places it face-up into a "discard pile". (Unlike in Rummy 500, only the top card of the discard pile is usable at any time, so the pile builds up straight, not fanned out.)
It is now the turn of the next person clockwise around the table from the dealer. A turn (from the first-person point of view) goes like this:
If there is a card in the discard pile, other players who have not "laid down" can "May-I?" the top card of the discard pile before I start my turn. If the card is "May-I?"ed, I have first dibs at it.
If I allow them to take the card, they must also take a card from the top of the deck (sort of as punishment for taking a card when it's not their turn). At this point, I may draw from either the top of the deck or from the next visible card in the discard pile. (I don't believe multiple "May-I?"s are allowed. I've never run into it.) However, if I DON'T allow the "May-I?", I must take the card from the discard pile. I may not deny a "May-I?" and then draw from the deck.
If more than one player yells "May I?", the first person wins. If it's a tie, the first person clockwise around the table from me wins. Also, a player may withdraw a "May-I?" and then other players may have a chance.
Each player is limited to 5 "May-I?"s (or a total of 21 cards in his or her hand) during each hand.
Once I have drawn a card, my goal is to create within my hand the combination of sets and runs required in order to "lay down" for this particular hand. If I get it, I may lay down the sets and/or runs in front of me. I may only lay down the exact number of sets and runs required by the rules of the hand. Extra sets or runs are not allowed. However, if anybody else has already laid down, and any of the cards left in my hand can be used to expand an existing set or run anywhere on the table, I may play my cards there. If I displace an Ace used to fill in a run, I may choose whether to move that Ace to the top or bottom of only that run. It may not be moved elsewhere on the table.
At the end of my hand, I must place a card from my hand into the discard pile. If I play all the cards from my hand during my turn, or if the card I place in the discard pile is my last card, I win the hand.
When a hand is won, all the players need to count up the cards remaining in their hands and report the point totals to the scorekeeper. Points are counted like this:
2-9: 5 points
10: 10 points
Jack-King: 15 points
Ace: 25 points
For the next hand, the next person clockwise around the tables shuffles and deals the cards.
The 7th hand (R R R) follows the same rules except for the following:
The hand may only be won by laying down your entire hand with no discard. This means if you don't "May-I" any cards throughout the hand, the card you draw for your turn must be the 12th card that fits into your hand creating the three runs. It ALSO means that if you DO "May-I" any cards, you must work those extra cards into your hand or get rid of them by discarding them during turns where you draw a card that fits in better. For this reason, people try not to "May-I" very much during the last hand so that they don't end up with a bunch of stranger cards they need to get rid of before they can "lay down" and win.
The scorekeeper keeps a running total of each player's points for each hand. The player with the least total points at the end of the 7th hand wins the game.
If anything is unclear, feel free to ask me about it. :) Keep in mind these are only the rules as my family plays them... I've never seen them published anywhere. If they are, they might be different.