Custom

Custom Mode

Custom mode is a new mode that was added in update 100. This allows the player to modify certain aspects to the game and their starting loadout.

This mode does not give unlocks and runs will not update character stats. For the most part it works independently of the save file, only pulling from it for the vanilla unlocks which can be adjusted in custom.

The following list is the first menu when selecting custom mode with an explanation of what they do.
Multiple of these options have sub-menus which are explained in full detail in the table below.

Start: Launches character select screen with the selected loadout
Slot: Allows for 9 preset slots, with any changes saved automatically

Unlike game settings this does not seem to cloud save, meaning presets are only saved on each local device

Loadout: Changes the player's starting loadout and their mutations
Generation: Changes how run generation should behave
Difficulty: Changes how some game mechanics behave during the run
Other: Gives an option to unlock all characters and crowns (does not include secret characters)

Setting Golden Frog Pistol as the starting primary weapon still works to play as Frog.

Reset Slot To Defaults: Works for that specific slot, with a warning to prevent misclicks

Loadout Options
Primary Weapon Secondary Weapon	Opens up menus to individually pick the primary and secondary starting weapons. All options for weapon starters will be sorted by what weapon class they are (Special, Melee, Bullets, Shells, Bolts, Explosives and Energy). Ammo melee will be grouped with their ammo type. Special Types: - Default on Primary will let the character choose between their default starting weapon or golden weapon that's unlocked in vanilla. - Default on Secondary will default to an empty weapon slot, aside from Steroids who always starts with a Revolver. - None will have that weapon slot be empty entirely, letting characters start runs without weapons. All secret weapons not normally seen in the drop pool are seen here, with the exception of the Electric Guitar alt. Some removed weapons are also included for loadouts including Sentry Gun (Bullets), Party Gun (Explosives) and Ion Cannon (Energy).
Proto Weapon	Selects which weapon will appear in the Proto Chest when opening it in that run. The weapons that appear here include any weapons that can also appear in primary/secondary weapon slots above. (Selecting None will default to the Rusty Revolver.)
Starting Mutations	Dictates what mutations will appear when starting a run, including all 29 options. This will also dictate what starting level the player is at, capping at level 9.
Mutation Choices	Dictates how many extra mutations will appear on the level up screen. The minimum is -3 to play like a Destiny run, while the maximum is +7 which gives a total of 11 mutation options at a time. A run with Crown of Destiny will only remove the base amount of mutations, with the modifier adding/subtracting afterwards.
Max Level	Dictates the maximum level the player can reach until hitting ultra, which is 10/9 by default. If the max level is lower than the starting mutations, then the starting level will be at ultra. The max level can exceed the amount of mutations in the game. If every mutation is picked the game will repeatedly grant Last Wish without any actual benefit. There is currently no known limit to the max level. (Further testing needs to be done on the rad differences for each level)
Level Cost	Slider that dictates how many rads are needed to level up. 1% will make any leveling up instantaneous when collecting rads while 200% will double the rads needed.
Level Ultra	Toggles whether ultra is given at the start of the run or not. If ultras are off and the number of starting mutations exceeds the level count, then the character will not receive an ultra choice at all.
Generation Options
Seeded Run Seed	Seeded Run will toggle whether a seed is available for that run. Once enabled the Seed can be modified which has a range of 999,999 numbers. (KBM setup: Unlike other settings the mouse cannot be used to modify the seed number. As usual movement keys work, but so does pressing number keys on the keyboard.)
Start At Loop	Dictates which area and loop the player should start in. Starting areas only include main areas, not secret ones. Starting loop can go anywhere from Loop 0 (preloop) to Loop 10. A normally inaccessible area in vanilla is starting a run on 0-1 on Loop 0, which starts the run with a low amount of IDPD and the Throne II fight, continuing to normal 1-1 afterwards.
Odd Areas Even Areas	Dictates how many levels should be in each odd area (Desert, Scrapyards, Frozen City and Palace) and even area (Sewers, Crystal Caves and Labs). Campfire is always one level. There is currently no known limit to the max amount of extra areas, while each has a minimum of 1. Levels will continue increasing in number such as 2-2, 2-3, so on. Boss levels will always be moved to the very last level, which includes even areas in loop. Secret areas will still function the same being one level, and will always bring the player to the next level of their original logic. A Vault on 3-2 will always bring the player to the next level logically. Meanwhile going to Pizza Sewers on 2-1 will always bring the player to 3-1, skipping any additional even levels. Extra areas will also add onto the difficulty as normal, every portal entered will still progress the weapon pool and increase the number of enemies each level.
Difficulty Options
Hard Mode	Toggles whether the run starts in Hardmode or not. If the generation value for loop is set to 0, then the run will start in H0, which is not normally accessible in vanilla. H0 will start similar to preloop, but all weapon drops will be a Screwdriver even if one is currently being held.
Damage To Player	Dictates how damage should be changed to effect the player, with the default being +0. The lowest amount is -10, although enemies will always deal a minimum of 1 damage. The highest amount is +10, making most enemy sources deadly.
Game Speed	Slider that dictates how fast the game speed is, with the default being 100%. Pause menus and loading screens are not effected. The minimum value is 10% making the game run at a snail's pace, while the maximum is 200% making the game run twice as fast.
Enemy Health Boss Health	Sliders that dictates how much health enemies and bosses should have. The minimum value is 10% giving enemies only a portion of their original health. Low HP enemies can immediately die to sources such as wall debris or corpse knockback. The normal maximum value is 200%, giving enemies twice the amount of health. However the slider has a secret setting (similar to the screenshake easter egg) where holding the right key (no mouse) to extend the slider beyond 200%. There is currently no known limit to the max value.
Pickup Timer	Slider that dictates how quickly pickups should fade away. The two second timer before pickups disappear is unaffected; what changes is the time before the blinking animation, meaning there is always a minimum of 2 seconds. The minimum value is 10% giving the shortest pickup timer, while the normal maximum value is 200%. Pressing the right button will extend the slider past 200%, with no current known limit to the max value.