Upon contact, you lose health but gain one to three coins (two to four coins with the PHD) (previously one or two, prior to the patch immediately following the Halloween Update); each one could be a penny, nickel or rarely, a dime.
After a random amount of donations, the machine will explode and reward you with a Blood Bag. Each donation has a 1 in 15 chance of causing an explosion.
With the Wrath of the Lamb DLC the Blood Donation Machine is also capable of dropping an IV Bag instead of a normal Blood Bag. There is a 50% chance for an IV Bag to be dropped instead of a Blood Bag.
Alternatively, you can destroy it with a bomb. This will destroy the Blood Donation Machine and give you a random drop of hearts and/or money.
How donating worksEdit
The machine will take hearts from your base health and will ignore your Soul Hearts unless your base health is at or below one half heart, in which case the machine takes Soul Hearts instead. It is possible to be killed by this machine.
In levels before The Womb, the machine will take a half-heart of health with each use.
In 'The Womb' levels and later, due to the persistent damage aura in that environment, the machine takes a full heart with each use. Additonally, it will not let you pay with soul hearts in 'The Womb' levels and later: if your base health is at one full heart or less, the machine will kill you, even if you have remaining soul hearts.
If you have the DLC Wrath of the Lamb, the machine will also now use Eternal Hearts before your base health.
Strategies for obtaining a Blood Bag / IV BagEdit
Every time you use a Blood Donation Machine, there is a 1/15 (6.66%) chance that the machine will explode into either the Blood Bag or IV Bag . This risk should be considered when pursuing the Blood Bag. However, it will not only grant an extra heart container, but it will also heal five hearts (thereby covering the cost of getting it in pre-womb levels). If the player enters an Arcade with enough pennies, it is almost guaranteed that a Blood Bag can be attained, as you can donate and then use the pennies on the other games to restore life to donate more. This method is especially effective when possessing the Lucky Foot, as winning at the shell game becomes a 50% chance. Should the player run too low on hearts, they can bomb it to try and replenish some of their spent health.
As of Wrath of the Lamb, gambling for a Blood Bag has become a lot more risky, since there is a 50% chance for the IV Bag to drop. However, unlike the Blood Bag, the IV Bag will not drop if you have previously picked it up. You can still find multiple IV Bags if you fail to actually pick it up when it spawns.
- Donating to the Blood Donation Machine is the method for unlocking Mom's Bottle of Pills.
- You can summon a Blood Donation Machine by using the Temperance Tarot Card.
- If you hit it right after having received damage from another source (including another Blood Donation Machine, but not the same machine) you won't take additional damage for a very short moment. You can use the machine freely during that time with correct timing.
- Due to the double damage, and thus double grace time, in The Womb, Sheol, Cathedral, and Chest, the same Blood Donation Machine can be used twice while only consuming one heart if done with good timing.
- As with all health-up items when playing with ???, the Blood Bag only adds one soul heart, making the Blood Donation Machine a bad trade option in general without the right items (see next note).
- There are many items that synergize with the Blood Donation Machine:
- The machine is triggered upon touch, so items that provide invincibility like My Little Unicorn, Book of Shadows or The Gamekid and A Pony allow using it for free.
- With The Habit, you can easily charge your activated items. If these provide you with new health, you can easily acquire high amounts of money and possibly even further health.
- These health-combos even work in The Womb, Sheol, Cathedral, and Chest if you use the strategy from the previous note of timing the second Blood Machine use during your invincibility 'grace time'.
- Yum Heart, Charm of the Vampire, and Little C.H.A.D. as these can create several hearts worth of health per level which can be spent on the machine. In Wrath of the Lamb, Child's Heart trinket is also very useful for the same reason.
- Whore of Babylon is great if you have soul hearts because it allows you to lower your health to half a heart while keeping your soul hearts. Additionally, right after the Whore of Babylon item is activated (when you get down to 1/2 a heart) you can quickly use the Blood Donation Machine again (Sometimes even a second time with perfect timing) without it removing your final 1/2 a heart.
- Keep this in mind when playing with Eve, who starts with this item and an increased chance to find soul hearts.
- Having the Bloody Penny will be a great help, as it has a 50% chance to drop half a heart upon getting a penny.
- If you have many heart containers, a Full Heath or Bad Trip pill are highly useful.
- If you have an attack fly, it may clone itself over the machine when using it. If this happens and you use the machine you will get a fly that acts similar to the ones that come with Friends till the End.
- When the machine drops either the Blood Bag or IV Bag it will show The Sad Onion for a half-second.
- If a machine on or after The Womb is used while a shield from Book of Shadows, Celtic Cross, or The Polaroid is activated, and the player's health is at exactly one half heart, and the player has any Soul Hearts, the player will lose half a Soul Heart and gain a half heart.