Jolly Co-Op

Jolly Co-Op is a local multiplayer gamemode introduced in the Downpour DLC. It allows up to four players to play and explore, , and 's campaigns, as well as Expedition, as any Slugcat. Slugcats other than Survivor and Monk must be unlocked by completing their respective campaigns. It is possible to play online via Steam Remote Play.

Player interactions

 * Slugcats have collision with each other.
 * A crouching or dead Slugcat may be grabbed by any other player. Holding pick up transfers the Slugcat onto their back. The throw button throws the Slugcat in the direction held. A held Slugcat can jump out of the grasp at any time.
 * This interaction is not dependent on whether the player is a Slugpup.

Food
Slugcats share the same food bar, determined by the current campaign. Any food can be consumed to add to the bar, regardless of whether Player 1 can eat it; however, individual Slugcats still have their own food limitations. For example, on a Expedition,  can consume Blue Fruit to add to the bar, but not Batflies. Meat-eating Slugcats are able to eat the corpses of creatures already leeched by Spearmaster, making this a convenient way to gain food.

Reputation
Each Slugcat has their own reputation counter and gain rate. For example, s are always hostile towards, even if another player has high reputation. However, upon payment, toll Scavengers allow all present Slugcats to pass (except Artificer).

Settings
Jolly Co-Op settings can be changed in its unique configuration menu toggled by the button in the top right of the Slugcat selection screen or Expedition mode. Slugcat selection is player-specific, while all other settings apply to the whole campaign. Settings may be changed at any time, including after starting a campaign.

Slugcat Selection
There are 4 settings that individual players may choose to customize their experience:

Slugcat: Allows players to choose which Slugcat to play. Multiple players may select the same Slugcat.

If Jolly Co-Op is enabled, but the number of players is set to 1, the first player may play through Monk, Survivor, and Hunter's campaigns as any Slugcat.

Color: If Custom is selected under the setting, players may customize their Slugcat's colors. This works identically to custom colors in single player campaigns.

Size: Allows players to switch between adult and pup mode. This is purely aesthetic and has no effect on gameplay.

Name: Allows players to insert a custom name; the defaults are 'Player 1', 'Player 2', 'Player 3', and 'Player 4'.

Difficulty
Jolly Co-Op offers three different difficulty settings to better cater to individuals looking for a more casual or hardcore playthrough.

In Easy mode, only one player needs to reach a shelter in order to hibernate.

In Normal mode, all players, alive or dead, must reach a shelter in order to hibernate; this requires other players to carry dead Slugcats to the shelter. If a Slugcat's body is destroyed or lost, the cycle must be reset, either by killing the remaining Slugcats or visiting an.

In Hard mode, all players must be alive and reach a shelter in order for to hibernate. Even if a player dies, the Game Over prompt does not trigger, so the only way to progress is to kill the remaining Slugcats or to visit an Echo.

Spears Hit/Miss
This setting toggles friendly fire. When toggled on, s thrown by players have collision with other Slugcats and are able to kill them. In addition, 's slam and 's stun and maul will be able to affect other players. When toggled off, player thrown Spears phase through any other Slugcats, and Gourmand and Artificer's special abilities do not trigger.

There are a few exceptions to friendly fire, most notably:
 * still hits players regardless of friendly fire being toggled on or off.
 * Projectiles fired by the hit players.
 * s are always lethal to all players if thrown at close range (With the exception of ).
 * s are always lethal to all players in the radius of effect.
 * s are always lethal to players if thrown at close range.


 * Saint can always Ascend players if max Karma has been reached.

Friendly Stealing
This setting determines if players are able to take items from another Slugcat directly. If turned off, players are required to drop items to exchange them with each other.

Friendly Lizards
This setting affects whether tamed are friendly towards all players, or just the one that tamed it.

Camera Cycling
When toggled on, pressing the Map button twice will cycle the camera to the next player. Otherwise, players can only request the camera for themselves.

Pipe Interactions
When Vanilla Pipes is on, Slugcats proceed through room transitions as normal. Otherwise, if the Smart Pipes setting is toggled, any Slugcat entering a pipe waits for a short amount of time before going completely through it in order to give other players a chance to enter.

HUD
When toggled on, players' names are displayed above their Slugcat using their main color.

Color mode

 * Default: Slugcats have their default colors. This may make it difficult to differentiate between identical Slugcats.
 * Automatic: The game automatically assigns colors to players.
 * Custom: Players may choose their own colors.

Bugs

 * Jolly Co-Op can cause the vanilla ending to not trigger properly, as the light teleports whenever Slugcat swims closer.

Trivia

 * The name "Jolly Co-Op" is a very likely a reference to a quote from Solaire of Astora from Dark Souls, of which he tells the protagonist to "...cross the gaps between the worlds, and engage in jolly co-operation!"
 * Player Slugcat kills count as 1 point.
 * Player corpses cannot be eaten, but can gain 1 food pip by spearing a Slugcat.
 * Spearmaster's weight is adjusted so they cannot infinitely fly by backflipping with a.
 * 's lung capacity is increased.