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Co-Op Overview

Vanilla Nuclear Throne offers two player local co-op. There is a mod for PC versions called Nuclear Throne Together (NTT) that offers 2-4 player co-op with local and online support.

Co-op largely follows the same mechanics as normal mode. Exclusive to this mode is reviving mechanics and unique ultras, which are covered in sections below.

If playing local co-op then at least one player has to use a controller. If the 'gamepad' option under control settings is set to off, then player 1 will use KBM while player 2 will use controller. If 'gamepad' is set to on, then both players can use controllers. The 2023 Steam beta allows for rebinding both controllers among other features.

Using golden weps or crowns in local co-op: Enter the normal menu first for a singleplayer run and select the desired golden weapons for both characters being played as. For crowns, select the desired starter for whoever Player 1 will select. Whichever is selected will be applied during co-op runs, which also applies to playing Frog. A run does not need to be started for these to apply.

Using golden weps or crowns in NTT co-op: Using /cwep [weapon] changes starting weapon and /ccrown [crown] changes starting crown. (Using /bwep [weapon] changes secondary too if so desired.)

Hardmode co-op is only available for local in the 2021 openbeta forwards, meaning it cannot be played locally in older versions. For NTT, using the /hardmode command will toggle it on and off

Run Mechanics

Players on local co-op will have the camera focus between the two players, meaning they must stick near each other constantly. Only when one player dies is the other temporarily given free cam.

What is shared between players:

• Rad meter: Players share leveling up and the rad meter for ultra weapon usage.
• Mutations: Either player can select a mutation on the level up screen, and it counts for both players.
• Crowns: Only one can be ran at a time.

What is unique for players:

• Weapons: Each player have their own two weapons. If they wish to trade weapons with each other this can be done with swapping a weapon on the ground.
• HP and Ammo pickups: These will only apply to the player who picked them up, even if they're full. Exception being co-op ultras.

Only one character needs to enter the exit portal in order to leave the area. Players cannot friendly fire each other except for projectiles that can also self-damage, such as disc projectiles or explosions.

Revive Mechanics

Co-op runs only end if all players are fully dead. If a player dies they'll have a 'FAINTED' sign over them and have a ghost-like state. If this ghost sprite is touched by an alive player, they'll gift 50% of their current HP rounded up. This cannot go above their max HP, so for example if base Melting dies only 2 HP would be gifted to bring them to full.

A 10 second timer will begin ticking down any time a player is killed. If they are not revived in time, then it will begin to damage the alive player at 1 damage a second.

If the alive player is only at 1 HP and they try to revive a player, they will then die and swap places. There is a cooldown of 1 second to reviving each other to avoid getting stuck, but otherwise players can chain revive each other to avoid the 10 second counter from running out while they search for health pickups. If at 1 HP with Strong Spirit, this will simply consume Spirit to give 1 HP without killing the player.

Dead players drop their weapons but will automatically be picked back up when revived. The exception to this is if the alive player gets sucked into the exit portal; both will be brought into the next level but the dead player will no longer have their weapons, unless if they happen to get pulled through as well.

If playing as Chicken, when taking a lethal hit she will enter her headless state before entering the fainted state, guaranteeing that she loses max HP. Chicken cannot revive other players while headless.

Crown of Death's death explosion applies even if just one player dies, which can kill other players if not running Boiling Veins.

Mutation & Passive Mechanics

Coming soon to a Wasteland near you!

Ultra Mutations

Vanilla NT removes character-specific ultras from co-op, giving the option between two ultras; Gun Bond and Blood Bond. NTT can either use co-op ultras or character-specific ultras using the /ultras command, but cannot run both co-op and character together.

Co-Op Ultra Mutations
Blood Bond	"HP Pickups Are Shared" The ultra A co-op option, it makes any health gained apply to both players. This includes health pickups, health chests and Bloodlust. (All sources will be tested later). Blood Bond will not cause dead players to be revived, but can save Chicken while she is headless.
Gun Bond	"Ammo Pickups Are Shared" The ultra B co-op option, it makes any ammo gained apply to both players. This includes ammo pickups and ammo chests. (All sources will be tested later). The player that picks up ammo will have the type chances apply to them, and then that ammo type will also be shared with the other player. Opening an ammo chest will give ammo specific to each players' primary weapons independent of each other. Lucky Shot gives the same ammo type to players, which is randomly chosen.