DELETE THIS

DELETE THIS is challenge #45. The goal is to defeat ???. This challenge is unlocked by unlocking Tainted Eden. During this challenge, all items are randomly generated by randomly combining effects from other items in the game. Item sprites and text are randomly generated as well, providing no information on what each item does.

In addition to gameplay changes, the theme of each area, its obstacles per area, and music are randomized. Some obstacle sprites are randomized even within a level and sometimes the music may be missing altogether. Occasionally, even the floor texture might glitch out, replacing it with a plain color.

Strategy[ | ]

Try to get an active item that has a low charge or does something beneficial. Be warned, as items are randomly generated, active items could also just damage the player.
Item prices in shops can vary significantly, from as low as a single cent to as high as 99 cents.
Trinkets, Pills, Cards and Runes are unaffected by the randomization that TMTRAINER forces on other types of items; finding good trinkets such as Curved Horn or Cancer, as well as saving powerful cards such as XIX - The Sun for bad situations, can help give advantages despite your lower-than-usual stats.
Due to the inherent random nature of items, direct stat ups are very rare. As such, Bombs and XIII - Death gain increased utility during this challenge, as their relatively high damage is unaffected by randomization.
Once you have a reliable strategy, stop taking items, as some of their effects (replicating Damocles or mass spawning enemies) can end the run.
Try to finish the challenge as fast as possible, as a game crash is always randomly likely to happen from picking up just one item.
Taking a Deal with the Devil should only be done when having a strong life bar: You have no guarantee to get a good item, so you might lose heart containers for nothing. Waiting for an Angel Room to spawn instead is a safer strategy.
The effects of items that you have not unlocked yet can still appear in this challenge, including active items, meaning that with patience and luck, a Mega Mush, or some similarly useful item, can appear and carry you through the entire run.

Notes[ | ]

It is possible for the challenge to be completed early if an item happens to spawn the ending trophy.
Conversely, it is possible for the challenge to have effects rendering it impossible, such as by destroying the ending trophy, or the challenge ending with a seeming victory but gaining no completion mark.
Due to the random nature of generated items, it is possible to find an item that makes completing the challenge trivial. Such as an active item with no charges, and deals damage to the whole room which can be spammed to clear each room. Or an item that grants a black heart whenever damage is taken which makes Isaac functionally invincible and causing mass damage whenever touched.
Unlike all other challenges, DELETE THIS appears below the challenge list itself, as an additional nameless challenge not numbered on the list.
- The blank space where the invisible challenge is located still gets crossed out after the challenge is complete, however.
All glitched items will appear as the icon for Mega Blast in the pause menu and death screen, though will keep their original glitched appearance on the Extra HUD.
You do not need to pick up the item that spawns after the Mom fight: Isaac will always be transported to the Chest after touching the golden chest that spawns in the Cathedral even if it doesn't seem like he has The Polaroid on him. This does not necessarily apply to golden chests randomly generated by items effects.
Some hardcoded items, like The Small Rock, Steam Sale, or Plum Flute might still appear normally.
TMTRAINER can be lost.

Reward[ | ]

Temperance - Complete DELETE THIS (challenge #45).

Trivia[ | ]

This challenge does not have a name in the game's files at all, and is not merely hidden from the menu: it is defined by the number 45 as its ID and has a zero-length character string for a name. For clarity, this challenge is referred to by the name of the achievement that unlocks it.
The name of the achievement for this challenge being unlocked and its description ("TODO: remove this achievement") are likely references to code commenting, a programming practice in which messages are inserted into the code to give instructions on what to do with the code. In this case, the achievement name and description would tell the programmer to completely remove the challenge at some point in the future, heavily implying that the challenge's existence is a programming mistake.
- The achievement's description is also unique among all the other achievements for unlocking a challenge, which all instead say "Unlocked a new challenge."
- This is reinforced by the achievement description for completing the challenge and unlocking XIV - Temperance? ("INVALID_DESCRIPTION"), which is also unique among both the reverse card unlocks and the challenge unlocks.
  - In card reading, XIV - Temperance? could be read as imbalance and overindulgence. Which could be referenced on the challenge's idea of using glitch items from TMTRAINER.
Unused enemies from Antibirth such as Nightwatch, Corpse Eater and Barfy can appear in this challenge, although it is very unlikely.