Card Games
Treys is a relatively simple, single-player card game. The basic goal of the game is to get rid of all your cards before you run out of moves. To start the game the top card from the deck is drawn and makes the start of the discard pile. You can get rid of cards by playing them on the top card in the discard pile, as described in more detail in the next section.
An example of the layout at the start of a game of Treys:

Objective
The objective of the game is to play all of your cards before you run out of moves.
Layout
Your cards are initially dealt in a 3x3x3 grid (there are three rows with three columns of cards stacked in piles of three). The top card in each pile is face up while the rest are face down. The rest of the cards remain in the deck except for the top card which you flip over to start the discard pile.
How to play
Cards can only be played on the discard pile if it’s value is adjacent but not identical to the top card in the pile (i.e. you can play a six and an eight on top of a seven).
Aces are high, twos are low and it does not wrap around (i.e. an ace can only be played on a king and a two can only be played on a three).
You can play a card from the deck at any time during the game.
You can only play one of your cards if it is face up and “open”. An open card is defined as being:
- The rightmost face-up card in a horizontal row or
- The bottom most face-up card in a vertical column
Once there are no more face-up cards in a row or column you must flip the next level of face-down cards in said row or column.
If a move leaves a column and a row with no face-up cards then the player must choose to either flip the cards in the row or the column, but not both. The one exception to this is when a row or column still contains no face-up cards after the other is flipped, in which case this second row or column should be flipped. There should never be a row or column with no face-up cards at the end of the turn and this exception ensures that.
Threes are wild
If you get a three from the deck then you can play any open card on it. If there is an open three in the game then it can be played as any card that can be played on the discard pile. It takes on the value of this card and is no longer wild after being played, even if it was played as a three on top of a two or four. A rare exception to this is when a wild three is played on a wild three (e.g. a three played off the deck) then it remains wild.
You can try playing and go through an interactive tutorial of Treys here.
Strategy
Although the gameplay is relatively simple, some basic strategy can make a big difference in whether you win or lose. For example, since threes are wild there are many more ways to play them than any other card.
However, twos can only be played on threes so if use up all of your threes early in a game then you have no hope of winning if you end up with a two towards the end. Therefor, a common strategy is to count how many twos have already been played and to be very frugal with your threes until you know that there aren’t any potential twos left underneath your cards.
Another example of strategic playing is being aware of what cards will become open after a certain move. For example, there are situations when you have two open cards that you are able to play and playing one of them will result in no new cards opening up (e.g. the bottom right card at the start of a game).
It will then usually be advantageous to play the other open card which will leave you with another open card to play on the next move. Another form of this type of strategy is to always prefer a move that will open up a Two. This way if you end up drawing a Three on your next card from the deck you will be able to get rid of the Two instead of “wasting” the three on another card.