The Binding of Isaac: Rebirth
637 Achievements
800-800h
Basement Boy
Beat basement without taking damage.
53.7%
How to unlock the Basement Boy achievement in The Binding of Isaac: Rebirth - Definitive Guide
The best tips I can give you is to familiarize yourself with the enemies and their movement/attack patterns. This goes for the bosses as well. Be cautious with spikes and fires for any misstep can cost you a run.
Also if you are able to get a solid item that can do A lot of damage on the first floor, it should help greatly.
Purchasing from a Deal with the Devil Room does count as taking damage
These do not count as taking damage
-Using the Blood Donation Machine or IV bag.
-Damage taken from the Devil Beggar.
-The "Bad Trip" or the "Health Down" pill effects.
-The Razor Blade and Blood Rights items.
-Using a "Health up!" pill.
-Taking damage while under the effect of Holy Mantle
Everytime you back out to the main menu you get an autosave. So keep that in mind.
After you've cleared one or more (how many you like) rooms without being damaged exit to the main menu to get another autosave.
In case you get hit you have to either let enemies, spikes or bonfires kill you or bomb yourself to death. This can be a tad annoying if you have 12 hearts towards the last couple of floors like the "Womb/Utero" or the Darkroom/Chest.
NOW THE IMPORTANT PART!!!
During the death animation pause the game and hit the guide button. Manually quit the game.
VERY IMPORTANT!!!
You MUSTN'T quit after being hit BEFORE you die. That way it would for whatever reason save your current health.
VERY IMPORTANT!!!
If you continue after starting the game up again you will be back where your last autosave was.
This works for THE LOST playthroughs as well!!!
Of course with him killing yourself is easier since he has no health and dies in one hit.
Items like Holy Mantle (you can take one hit every room), the "9 lives cat head" or guppy's collar (1 extra life) can change this, though.
Avoid the Ankh at all cost since it respawns you as another character and would therefor void the achievement.
So just pray to the RNG God to be lucky with drops and this is going to be a breeze. Time consuming but easy.
Good luck everyone!
If you vote negatively please state why in the comments so I can improve my solution. I know some people prefer going for this legtit but this is for gamers like me that don't have enough skill to attempt it that way.
Things that DO NOT count as "taking damage" (props to Insane Fallout on True Achievements)
-Using the Blood Donation Machine or IV bag.
-Damage taken from the Devil Beggar.
-The "Bad Trip" or the "Health Down" pill effects.
-The Razor Blade and Blood Rights items.
-Using a "Health up!" pill.
-Taking damage while under the effect of Holy Mantle
If you've unlocked Judas, it may be worthwhile to use him to unlock this achievement, as he hits harder than most of the base characters. And since you're not getting hit, the fact that he only has 1 heart is irrelevant.
For the most part you can't take any kind of damage, this includes Soul Hearts and Black Hearts. Making a deal with the Devil will also void the achievement for the current floor. My best advice is to memorize enemy movement patterns and learn how to dodge enemy fire. I also recommend attempting this after unlocking the item There's Options, which is a store item that will spawn two items after killing a boss instead of one, but only allowing you to take one of the two, this will help maximize the value you can get out of the boss room item pool.
The following circumstances do not count as taking damage:
- Taking damage while under the effect of Holy Mantle.
- Self damaging items such as Razor Blade.
- Bad Trip" or the "Health Down" pill effects.
- Damage taken from the Devil Beggar.
- Using the Blood Donation Machine or IV bag.
The main idea for these achievements are to try and get a "glass cannon" run. If you have the choice between DMG or HP always take the DMG up, since you are trying to not get hit anyways. Also best done on normal mode. some really good/overpowered items to look out for are: Trinity Shield, Polyphemus, Mutant Spider, Mom's knife, IPECAC, Head of Krampus, Cricket's Head, Brimstone, Sacred Heart, Holy Mantle any of these items, or a combination of them have the potential to completely break a run, making all these achievements a cake walk.
Then accumulate a second charge and use it again, you don’t even need to kill the boss