On Racing+, players have the option to choose from different kinds of races.
Regardless of the format:
- The Polaroid or The Negative will be automatically removed depending on your run goal.
- The trapdoor or the beam of light on Womb 2 will be automatically removed depending on your run goal or which photo you have (if you have the Fast-Travel feature enabled).
- Historically, most races have been unseeded. This means that both players start with the same character but play on different seeds.
- Each player is allowed to reset as many times as they want. Typically, each player will reset over and over until they find a good starting item from the Basement 1 Treasure Room.
- In seeded races, all players play on the same seed. (This means that they should get all of the same items, bosses, and so forth.)
- Resetting is allowed, but it will just take a player back to the beginning of the same seed.
- Each player will start with a pre-defined starting item that is chosen before the match, such as Cricket's Head or Mom's Knife.
- The Basement 1 Treasure Room is removed. (This is to prevent players from starting with 2 items instead of 1.)
- All characters start with The Compass in addition to their other items (to mitigate floor RNG).
- Instead of dying, players will respawn in the previous room with 1.5 soul hearts.
- They will have a "debuff" effect that removes all of the items. The debuff will last 45 seconds.
- This mechanic does not apply to deaths in Devil Rooms, Sacrifice Rooms, or the Boss Rush. (Deaths in those rooms will be permanent.)
- Black Candle is removed from all pools (since it changes level generation).
- Sol is removed from all pools (since it is practically useless if you already have the Compass).
- Glyph of Balance is removed from all pools (since it changes drop-generation).
- Duality is removed from all pools (since Devil Rooms and Angel Rooms are seeded).
- Damocles is removed from all pools (since the killing mechanic is unseeded).
- Birthright is removed from all pools if the starting character is Cain (since it changes floor-generation).
- Birthright is removed from all pools if the starting character is The Lost (since it changes pools and causes Judas' Shadow to be removed).
- Cain's Eye is removed from the trinket pool (since it is useless if you already have the Compass).
- Silver Dollar, Bloody Crown, Telescope Lens, Holy Crown, and Wicked Crown are removed from the trinket pool (since they change floor-generation).
- Dice Bag is removed from the trinket pool (since it is not seeded properly).
- Modeling Clay is removed from the trinket pool (since it causes items to be erroneously removed from pools).
- Daemon's Tail, Child's Heart, Rusted Key, Match Stick, Lucky Toe, Safety Cap, Ace of Spades, Watch Battery, and Nuh Uh! are removed from the trinket pool (since they change drop-generation).
- Players will get either all Devil Rooms or all Angel Rooms, with a 50% chance of each based on the starting seed of the run.
- Bethany and Tainted Magdalene will always get Angel Rooms.
- The following things are guaranteed to be seeded:
- Room drops (given in order, regardless of luck)
- Level generation (consistent special rooms, regardless of inventory status)
- Devil Room layouts and items (given in order)
- Angel Room layouts and items (given in order)
- The following things no longer affect room drops:
- Luck (always uses a value of 0 luck)
- Rib of Greed
- Smelter
- Guppy's Tail
- 3 Dollar Bill is seeded per room.
- Magic 8 Ball no longer increases the chance for a Planetarium to spawn, because level generation is always the same.
- Not entering a Treasure Room no longer increases the chance of a Planetarium appearing, because level generation is always the same.
- Diversity races are similar to unseeded races in that each player plays on different seeds and is allowed to reset as much as they want.
- However, each racer starts with the same five random items. (This is in addition to the character's original passive items and resources.)
- For additional information, see the documentation for diversity races.
- There are no additional changes to the game in this format.
- Custom allows people to race with their own custom rules. For example, you could make a race where you are not allowed to pick up any Devil Room items.
- Make sure that everyone in the race knows the rules before starting.
- This option is used for multi-character speedrun races.
On Racing+, players have the option for races to end at different places.
- Historically, most races have had the goal of killing Blue Baby, the boss at the end of The Chest.
- There are no additional changes to the game for this goal.
- The Lamb is the boss at the end of the Dark Room.
- The spikes in a Sacrifice Room will be deleted after the 11th sacrifice.
- Mega Satan is the boss behind the giant locked door. Players are allowed to take either path to get to Mega Satan.
- The door to Mega Satan will automatically open upon reaching The Chest or the Dark Room.
- The spikes in a Sacrifice Room will be deleted after the 11th sacrifice.
- Hush is the boss in the Blue Womb.
- Trapdoors and beams of light will be deleted on floor 8.
- After killing Hush, the door to The Void will be deleted.
- Delirium is the boss in The Void.
- Trapdoors and beams of light will be deleted on floor 8.
- Mother is the boss at the end of Corpse 2.
- Normal trapdoors will not spawn. The doors to the Repentance alternate floors will be automatically opened.
- We Need to Go Deeper will only work on odd numbered floors (because you are supposed to go to the secret passage on even numbered floors).
- The Beast is the boss at the end of the Ascent.
- The trapdoor after defeating Mom take you to Mausoleum 2 instead of Womb 1. (There is no need to use a Fool card.)
- Boss Rush is a special encounter at the end of floor 6.
- Trapdoors will be deleted on floor 6.
- There are no additional changes to the game for this goal.
- Custom allows people to race with their own custom goals. For example, you could make a race where the goal is to beat Mom as fast as possible.
- Make sure that everyone in the race knows the goal before starting.
- This option is used for multi-character speedrun races.