Hanabi is a cooperative card game where you can see everyone's cards but not your own. The deck consists of 50 cards in 5 colors; each color has three 1s, two 2s, two 3s, two 4s, and one 5. The goal is to build up five stacks of each color from 1 through 5, like in solitaire. The team starts with 8 clue tokens(see 2c below).
You have three options for each turn:
Play a card: A player can pick a card from their hand and attempt to play it.
If it's the next card for any of the five colors, it gets played onto that pile. You don’t need to know specify which pile in advance! As long as it fits, it's OK.
Small bonus; Successfully playing a 5 gives the team an additional clue.
Otherwise, the team gets a strike, and 3 strikes ends the game.
Discard a card: A player can pick a card from their hand and discard it. The card goes to the discard pile and the team regains an additional clue. This option isn’t allowed if the team has all 8 clue tokens already.
Spend a clue: A player can spend one clue token to give information to another player. They choose a player and either a number or a color, and then tell which subset of their cards matches the clue. The subset must be nonempty.
Assuming the team does not strike out, the game ends after the last card is drawn from the deck and every player takes one more turn. Your score(out of 25) is the number of cards played successfully.
Rules of the game (adapted from here)