Cuttle is a two player card game played with a standard deck of 52 playing cards and is the earliest example of a combat card game. The game's earliest confirmed appearance took place in the 1970s, though the exact date of its creation is unknown.

Objective 
The objective of cuttle is to have 21 or more points in-play under one's control at any time. Points are acquired by playing any card which is not a face card to obtain the number of points represented by that card (with aces being worth one point, twos being worth two points, etc.) In order to reach 21 points before their opponent each player must attempt to use their turn most effectively.

Mechanics 
These are the standard mechanics as proposed in the earliest surviving ruleset. Several variations on these mechanics exist.

Playing a Card for Points 
When playing a card for points the player removes the card from their hand and places in front of them. Once a point card has been placed on the table it is considered in-play. Point cards which are in-play should be made distinctly separate from each player's layout and be visible to their opponent. Point cards which are removed from play in any way are placed in the universal discard pile.

Playing a Card as a One-off 
When playing a card as a one-off the player removes the card from their hand, alerts their opponent to the one-off ability of the card, and places it immediately into the universal discard pile. If there are no mitigating factors the effect of the card is then evaluated.
The following table enumerates each of the cards which may be played as one-offs and their abilities:

Adding a Card to the Layout
Each player maintains their own layout. These are cards which grant the controlling player a permanent gameplay effect until they are removed from play by another card.
The following table enumerates each of the cards which may be added to the player's layout and their effects:

Exceptions
Several of the cards in cuttle behave differently from standard one-offs or layout cards. They operate as follows:

Scuttling 
Scuttling is the act of using a card with a higher point value to force an opponent to discard one of their in-play point cards with a lower value than the card being used to scuttle. The card being used to scuttle is also discarded. In the event that two cards have the same point value the ability to scuttle another card is determined alphabetically by the name of the suit: Clubs - Diamonds - Hearts - Spades. If two cards have the same point value any card from a suit which before it in alphabetical order may be used to scuttle it.

Gameplay 
A game of Cuttle begins with a deal and then consists of the two players taking alternating turns.

Dealing 
At the beginning of the game a dealer is chosen randomly. The dealer deals five cards to their opponent and six to themself. These cards form the initial hands of both players. The remaining cards are placed face down between the players and become the draw pile.

Turns 
Turns alternate between each of the players beginning with the player who did not deal. On their turn a player may choose to do one of the following:
 Draw a card from the draw pile and place it in their hand
 Place a numerical card from their hand onto the table in order to obtain the corresponding number of points
 Place a card which may be used as a one-off into the discard in order to utilize its ability
 Place a card which may be used as a layout card in front of them to begin benefitting from its effect
 Place a card which can scuttle one of the opponents point cards on top of it and then move both cards into the discard pile
After performing their desired action the players turn is over and their opponent's turn begins.

Winning 
As soon as one player's score reaches 21 or more the game is over, with the player who has matched or exceeded 21 points being declared the winner. This can happen on either player's turn.

Variations 
There are many variations on Cuttle. Several variants are listed below.

cuttle.cards Vanilla 
Online play at cuttle.cards uses several minor changes to the rules written above, in order to fine-tune the game's balance for competitive play:
 The most important change is the addition of an 8-card hand limit. Players cannot draw when they have 8 cards in hand and playing a 5 when you have 8 cards already draws you just one card so you go up to 8.
 Seven one-offs: reveal the top two cards of the deck (instead of one), and the active player chooses one of the cards to play, and puts the other back on top of the deck.
 Nine one-offs: return target permanent to it's controller's hand. It cannot be played next turn.
 Having 3 kings reduces a player's goal to 5 points (from 7), and having all 4 kings reduces a player's goal to 0 points (from 5) and causes that player to immediately win.

Cutthroat Cuttle (1v1v1) 
Cutthroat is a fast-paced 1v1v1 version of Cuttle. It is played with the same rules as the cuttle.cards Vanilla rules, with the following changes:
 The win condition is reduced. Players need 14 points to win by default, 9 points with one King in play, 5 points with two Kings in play, and having 3 Kings in play immediately wins (goal becomes zero).
 To start play, deal each player 5 cards and the player to the left of the dealer goes first. Which player is the dealer rotates clockwise each game.
 Shuffle two Jokers into the deck. Jokers count as Royals with the effect "Steal target Royal".
 The hand limit is reduced to 7 (from 8).
 When playing a glasses 8, instead of forcing players to play open handed, the player with the glasses may request to see either opponent's hand at any time

Team Cuttle (2v2) 
Team Cuttle is a 2v2 game where players sit across from their partner. A team wins if either of its players earns the required number of points, but players do not share cards in their hand or on their field (points are counted separately and your Royals do not directly affect your partner). Otherwise, the rules are the same as cuttle.cards Vanilla Cuttle, with the following changes:

 Each player is dealt 5 cards, play starts left of the dealer and proceeds clockwise from there.
 Shuffle two Jokers into the deck. Jokers count as Royals with the effect "Steal target Royal". Similar to Jacks, they may transfer control of a Royal from any player to any other player.
 The hand limit is reduced to 7 (from 8).
 Jacks may be played to transfer control of any point card to any other player. You may therefore "steal" points from yourself (or anyone else) in order to give them to your partner, potentially winning on your turn with their points (their goal is still determined by the count of their own Kings on the field).
 Nines can be played for an alternative, similar effect. Whenever an opponent plays a Royal, you may immediately play a Nine in response to return that card to its owner's hand immediately, preventing its effect from taking place. Doing so may be done out of turn and does not take your turn, but does not prevent the target's owner from playing the card again on their next turn. Alternatively, you may still play a Nine for its original one-off effect on your turn (taking your turn to do so) to return a card to its controller's hand and prevent them from playing that card on their next turn.

Competitive Cuttle 
The largest and longest-running competitive Cuttle league is hosted online at cuttle.cards. Players compete online in 1v1 matches that qualify them for Season Championship tournaments, and the top competitors in the Season Championships earn places in the annual Cuttle World Championship.

Competitive Format 
Competitive Cuttle divides the 52 weeks of the year into 4 seasons: Clubs, Diamonds, Hearts, and Spades, spanning 13 weeks each (mirroring the composition of a standard deck of 52 playing cards. Play is generally structured around first-to-two-wins matches (like best 2/3, but where stalemates are ignored and play continues until one player reaches 2 wins) between two opponents. Every week, players earn points for the number of matches they win against unique opponents relative to other players, as follows:

At the end of each 13-week season, the Top 8 Players earn places in that season's Championship tournament. Contestants in those tournaments earn points towards a place in the annual Cuttle World Championship as follows:

At the end of the year, points are calculated from the 4 Season Championships (Clubs, Diamonds, Hearts, and Spades), and the Top 8 players with the most points earn places in the Cuttle World Championship.

History of Competitive Cuttle 
Below is a record of the Cuttle tournaments that have taken place throughout the game's history.

Clubs 2023 
The Clubs 2023 season of competitive Cuttle ran from 2023/01/04 - 2023/04/05. The Clubs 2023 Season Championship tournament was a Double-elimination tournament with 8 competitors who placed as follows:
 SUBMARINO
 lanceleyn
 Eorgosa
 aleph_one
 gman232
 ButterBothSides
 dp
 bbjme

2022 Cuttle World Championship 
The 2022 Cuttle World Championship was held on 2023/01/04. It was a Double-elimination tournament between 12 contestants, who placed as follows:
 gman232
 dp
 hfromeo2
 aleph_one
 launceleyn & SUBMARINO (tie)
 pfCuttle & DanMan422 (tie)
 Eorgosa, Mxyon, byarmis, & dylanfryer (tie)

References

French deck card games