Familiars dead characters have will despawn, making their absence much more impactful make sure to give them to characters who are more likely to survive.

Because all dead characters are revived after clearing a Boss Room, more frail characters (like The Lost, Keeper, and Tainted Jacob) become much more powerful, as they can afford to die the other characters just have to complete the floor with less help if they do.

With the help of a Library, all characters can easily acquire the Bookworm transformation.

Active items can be juggled between all characters to give them progress toward transformations.

If one character has Butter!, it can be dropped and given to the character who wants to swap items, circumventing the need for another active item altogether.

Active items can be traded between characters by swapping them with other active items on pedestals.

Take note if one player has a penny trinket (such as Bloody Penny or Counterfeit Penny), since the trinket effect will only trigger for the player who takes the coin.

Because all coins, bombs, and keys are shared, it usually doesn't matter which player takes them.

If one of the items available is much better than the others, it's usually not worth the risk of getting the timing wrong and losing the powerful item.

With proper timing, this can be used to get more value out of these rooms.

If multiple characters touch different items at the same time in a room that offers multiple choices between items (such as Angel Rooms, alt path Treasure Rooms, or Boss Rush), all the items touched will be taken before they despawn.

Consider who needs or can make use of certain items more than others when deciding who to give items to.

As items, trinkets, and cards/pills aren't shared between characters, players will have to choose who gets any given item.

For example, only the character that has BFFS! will have stronger familiars, and only the character that has Bloody Penny will spawn hearts from picking up coins.

If a character has an item/trinket that boosts the value of certain items/pickups, it will only apply to them.

Items that increase Devil Room chance will help everyone earn them, but one character taking red heart damage will hurt everyone's chances at earning them.

All players can affect Devil Room chance in all the normal ways, and all players will feel the effects of anything that changes it.

Enemies will target any players that are alive at random.

All characters will earn completion marks on their post-it notes and their associated achievements after completing their required objectives, regardless of how much they participated.

When a Boss Room is cleared, all dead players will respawn with half a heart (depending on what character they are playing). They can still flip switches on the ground and shoot tears, although they will deal 0.5 damage. These babies cannot fly (unless the character has an inherent flight ability, like The Lost or Azazel), aggro enemies, pick up items, or use any active items, cards, or pills they're holding.

Players who die will turn into small ghost babies upon death.

Void, Abyss, Eternal D6, Crooked Penny or Black Rune), no extra items will spawn after it.

Any item pedestals spawned in Boss Rooms will have this mechanic replacement items will always be from the Boss Room item pool, regardless of how they were spawned.

Boss Rooms drop an extra item for every extra player when the original item is taken, the other items will spawn afterward.

Certain changes are made to the game whenever multiple player characters are present.

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