Poker is a name used to describe a wide range of games that perhaps have 
very little in common.  In its most basic description, poker is a game 
played by 2 or more players with one deck of cards, in which each player may
place "stakes" in a "pot" during one or more "betting rounds", all 
leading to a possible "showdown" in which a player's "hand" is evaluated 
on a value system against other players' hands, and one or more winners 
lay claim to the pot.
The two most basic shared concepts in poker are those of "betting rounds" 
and "hand values".

A _betting round_ is a situation in which players have the opportunity to 
do one of three things:  check/call, bet/raise, or fold.  
 Betting begins with one player (there are various methods of selecting 
which player acts first) and then continues clockwise around the table.  
When it is a certain player's turn, that player is said to _have the 
action_ or be the next person to _act_.  Initially, the player with the 
action has two options:  he can "check" or he can "bet".  
  A _bet_ is an increase in the player's monetary commitment to the pot 
(his share is commonly refered to as his _stake_.  The _pot_ is the sum of 
every player's individual stakes).
  A _check_ is an indication that the player wishes to remain eligible to 
win the pot, but does not wish to make a bet at this point.
 Either way, action is passed on to the next player.  If the previous 
player has chosen to check, the next player faces the same check or bet 
option as the previous player.  If the previous player bets, the next 
player now has an obligation to at least match that bet if he wishes to 
remain eligible to win the plot.  His options at this point are: call, 
raise, or fold.
  A _call_ is an indication that a player wishes to remain elibigle to 
win the pot but does not wish to increase his stake in it.  He matches the 
previous player's bet exactly.
  A _raise_ is an indication that a player wishes to remain eligible to 
win the pot AND wishes to increase his stake in it.  He wagers an amount 
that exceeds the bet of the previous player.
  A _fold_ is a discarding of a player's hand and removal of his 
eligibility to win the pot.  He does not have to match the previous bet but he 
forfeits all moneys he has put in the pot so far.
 Once the player acts, action moves to the next player and he has a 
similar set of options.  Once a bet/raise is made, the betting round 
continues until action returns to the person who made the last 
bet/raise (he does not get to act again).  
Therefore, the betting round ends when:
  1.  All players check.  All players remain elligible to win the pot and 
the pot is not increase during that betting round.
  2.  One player bets or raises and all remaining eligible players act 
by calling or folding (no re-raises).
    a.  If one or more person calls, all persons who called and the last 
person to raise remain elligible to win the pot, now increased by all the 
indivudal stakes placed during that betting round.
    b.  If one person wagers and all others fold, that person is declared 
the winner and is given the pot.  

The final step of any poker game is the "showdown".  At the completion of 
the final betting round, all remaining hands are evaluated against each 
other on their value.  The _value of hands_ are determined by 
categorizing the "hand" (a _hand_ is a set of five cards) into one of these 
categories, in order of decreasing value.
1.  Straight Flush* : Five cards "in a row", all of the same suit.
2.  Four of a kind  : Four cards of the same rank and any other card.
3.  Full House      : Three cards of one rank, two other cards both
		      of an equal rank different from that of the first three. 
4.  Flush	    : Five cards of any rank all of the same suit.
5.  Straight        : Five cards of mixed suit all in a row.
6.  Three of a kind : Three cards of one rank and two cards of different 
		      other ranks.
7.  Two pair 	    : Two cards of one rank, two other cards both of a 
                      different rank, and another card of a different rank.
8.  One pair	    : Two cards of the same rank and three other cards, 
		      all with mutually unequal ranks.
9.  Nothing	    : Five cards containing no ranking pairs and no set 
		      of five cards either of the same suit or in a row.

 _Rank_ is a card's numerical value.  Number cards have their number as 
values, face cards outvalue all number cards and have increasing value 
J-Q-K, and Aces can be either the most or least valueable card, whatever 
makes the more valuable hand.
 Cards are said to be _in a row_ if they form a sequence of consecutive 
numbers (or face-card/numbered card combinations) such that there is a 
stepping value of one connecting all cards.
 *In some variations there are cards, called _wildcards_ which can be 
used to describe any possible card, normally whatever card would make the 
hand most valuable.  In such games, a new hand "Five of a kind" is 
usually introduced, which is more valuable than all other hands.
 
 Once hands are assessed into one of the above categories, hands in 
higher categories are declared more valuable than hands in lower 
categories.  If there is one hand that is clearly most valuable, it is 
declared the winner, and awarded the pot.  If, however, there are two or 
more hands that are of the same category, the following rules are used:
 1.  In straights, flushes, and straight flushes, a hand is more valuable 
if its highest-ranking card is more valuable than the highest-ranking 
card of someone else's hand.  If they are the same, the next highest card 
is used for determination, and so on.  If all cards are the same, the 
hands are declared of _equal_ value and the pot is divided between the 
hands.  AT NO POINT are suits used to determine the winner of 
equal-valued hands in a showdown.
2.  In 4-of-a-kind, 3-of-a-kind, and One pair situations, the higher 
ranking 4-of-a-kind, 3-of-a-kind, or pair wins.  If two hands have the 
same pair (or three and four of a kind in wildcard games), each other 
card in each hand is compared in order of decreasing rank. if all cards 
are of the same ranks, the hands are said to be equal.
3.  In a full-house, the rank of the three of a kind is used first in 
determening value (then the rank of the pair, in a wildcard game).
4.  In a two-pair situation, the higher pair is compared for rank, then 
the lower pair, then the remaining card.
5.  If both players have nothing, cards are compared in order of 
decreasing rank (high card wins).