These rules are summarized from the rules page on Pagat.com.

Hoola is a Korean rummy game that uses a standard international 52-card deck. Aces are worth 1 point, 2-6 and 8-10 are worth face value, jacks 11 points, queens 12 points and kings 13 points each. Sevens are special cards which are worth 7 points when going out with a 'blast' but 14 points when they remain in a player's hand at the end of the play.

The objective is to form melds. A normal meld is three cards in a set (such as 2-2-2) or a run in the same suit (such as 2-3-4 of spades). A run can "wrap", meaning that K-A-2 is valid. You can also play a special meld, which is a 7 on its own. A player can also add cards to an existing meld on the table.

A normal turn consists of:

1. drawing one card from the top of the stock pile or discard pile
2. optionally placing one or more melds from hand face up on the table
3. optionally extending melds that are already on the table by adding cards to them to make larger melds
4. discarding one card face up on the discard pile.

Step 1 is compulsory - every turn begins by drawing a card. Step 4 is also compulsory unless the player ends the play by melding all their cards and thereby going out.

There are five ways that the play can end.

1. The Blast

If at the start of any turn you have not yet melded any cards, and the total value of the seven cards in your hand is 15 points or less or 83 points or more, you may stop the game and win. For this purpose Sevens count 7 points.

2. The Knock (or Stop)

If at the start of your turn you have not more than 10 points in your hand then you may stop the game. Everyone immediately shows their cards. If you have the fewest points in hand you win, but if any other player has the same number or fewer than you, you lose. For this purpose sevens count as 14 points. (Note that when a player knocks it is not possible for the knocker or any other player to dispose of any cards by melding. All cards held in the hand at that point are counted.)

3. Going Out

If during your turn you meld all your remaining cards, either by making new melds or adding them to melds, or if you meld all but one of your remaining cards and discard your last card, the play ends and you win.

4. Four sevens (the big luck)

A player who has four sevens in hand can stop the game and win. Note that the sevens all have to be in the player's hand - if any sevens have been melded this type of win is not possible. This win can be played as soon as the fourth Seven is acquired - for example immediately after drawing it from the stock. The player does not have to wait until their next turn.

5. End of Stock

If a player draws the last card of the stock, that player completes their turn in the normal way. If they do not go out, then after they discard the play ends. No one can meld any further cards. The players show the cards remaining in their hands and count their points (7's count 14 points). The player with the lowest value of unmelded cards wins.