source:  http://www.rubl.com/rules/gin_rummy_rules.html

Number of Players
Gin-Rummy is a two-player card game.

The Deck
Gin is played with a standard 52-card pack of playing cards. Aces are
played only as low; the ranking from low-to-high is
A-2-3-4-5-6-7-8-9-10-J-Q-K.
The cards have values as follows: Face cards (K,Q,J) 10 points, Ace 1
point, Number cards are worth their value.

Dealing
The dealer to the first round is chosed randomly, dealership alternates

from round to round. The dealer deals 10 cards to each player, face
down, one at a time, alternately. The 21st card dealt, called the
"upcard", is placed face-up in a central location known as the discard
pile. The remainder of the pack is called the "stock" and is placed
beside discard pile.

Object of the Game
Each player tries to form "melds" which consist of three or four cards
of the same rank called "set" or "group" (such as the 2 of hearts, 2 of

diamonds and 2 of spades), or "sequences" (or "runs"), which are three
or more cards of consecutive rank in the same suit (such as the 2, 3, 4

of hearts). A second objective is to reduce the count of the unmatched
cards in a player's hand to less than the count of his opponent and the

summary value of these unmatched cards.<BR>
A card can belong to only one combination at a time - you cannot use
the same card as part of both melds.

the full article:  http://www.rubl.com/rules/gin_rummy_rules.html