Combilet is a combination letter game consisting of 76 cards. Each card has four selections of single and two letter combinations. The red side is made up of consonant-vowel, and vowel-consonant combinations, such as SA-AS, and the black side is made up of either two single letters, or a single letter and a double consonant, such as PR, TH etc., with some exceptions.
"The selections on each card are listed on the upper left hand corner. [Note there are four upper-left corners depending on how you orient the card, each one having a different selection in large font.]
—description from the rulebook
There are rules for 3 games:
Combilet
Each player has a 5-card hand. On their turn a player may do one of these:
Play a word of 5+ letters from the hand in front them.
Play a word of 3 or 4 letters from the hand to a common pool.
Take a word from the pool by adding cards that make it a 5+ letter word.
Take a word from another player by using cards that increase it, change it, or replace single letters with 2-letter combinations.
Then they fill their hand back out to 5 cards. Play presumably goes until the deck runs out or some other end condition is reached.
Each word's score encourages using 2-letter combinations: its score is 5 points each for the first two combinations, 10 points each for each combination beyond two, and 1 point for each single-letter card in the word.
Fast Combilet
Each player gets 5 cards which they try to make one or more words out of. Scoring is similar to that in regular Combilet. The player with the highest-scoring hand gets his score and that of each other play.
Solitaire
The deck is split into 5 piles, and the player makes words from the top cards, laying them aside and trying to finish the whole deck.
—user summary