Here's an overview of what the typical game screen
looks like during play:
As you can see, each tile you have in your hand has a letter
associated with it. That letter, of course, is the letter on the
keyboard. Select tiles by pressing the keyboard letter
beneath it.
Note that in the Dead Pile, 4 tiles on top are
unrevealed. Each time someone declares a Kong, a new tile on top
is
revealed as a Dora Indicator. Since there is only 4 tiles on top
that
can be revealed, it means also that only 4 Kongs can be made per
round. Generally, only 4 Kongs can be declared per round in
mahjong. Kongs can no longer be made once the limit is reached. The Dora Indicator is explained in more detail in the "Special Rules" section.
A Reach Stick is place on the table whenever someone declares Reach. The Reach Stick is explained in more detail in the "Scoring" section
There is a prevailing wind for each round. At the start of the match, the wind of the dealer is the prevailing wind. However, it will change as the match progress in later rounds. It generally changes after dealership has switched between you and the opponent two times.
Each player places their discards in their own separate
discard pile in front of them. Discards are faced up so that the
other player can see them and determine whether or not they can
make use of it themselves.
Discards are place from left to right in a row. Usually a new
row of discards form below or on top the initial row if there is no space
left on the table.
Each player has a score. When someone wins, their hand is
scored and their score is increased by that amount while the
other players score is deducted by that amount. Scores may also
increase or decrease in other situations, like when Reaching or
in Tenpai/No-ten situations. When a player's score is zero or
less, that player loses the match.
Here's another screen:
Dealer's Counter and Reach Counter are explained
in the "Scoring" section.
Note in the dead pile that there are 2 stacks of unrevealed tiles to
the left and 4 stacks of unrevealed tiles to the right of the Dora Indicator.
The fourth stack of tiles to the right is
not currently displayed on the screen. Only
tiles on top to the right can be revealed as Dora Indicators when a Kong is declared.
The 2 stacks to the left are loose tiles. They are the tiles taken
whenever a Kong is made. Similarly, since there are only 4 loose tiles
that can be taken, only 4 Kongs can be made per round.
Loose tiles are, often times, not displayed on the
screen as can be shown from the first screenshot.
Another screen:
Some games position the dead pile the other way
around. In this case the 2 stacks of tiles to the right are the loose tiles,
while the 4 tiles on top to the left can be made into Dora Indicators
whenever a Kong is made.