Donation Machine



The Donation Machine is a type of machine that appears in almost every Shop as well as rarely spawning through Black Markets, Reward Plates, Arcades, and Vaults.

Upon touching the Donation Machine, Isaac will donate a coin, causing the displayed coin total to increase by one. Similar to the Greed Donation Machine, the number of coins donated will persist between runs. Donating money will both upgrade the Shop and unlock new items.

It will take the player many runs of continuous donations to unlock everything, as the player will have to donate a total of 999 coins to max the machine out.

Mechanics

 * Every donation made to the Donation Machine on a single run has a 5% chance to jam the machine. Once the machine is jammed, no more coins can be donated to it until a new run is started.
 * On average, a Donation Machine will accept about 15 coins before jamming on every run.
 * Bombing the Donation Machine in any way will cause it to drop 1-5 pennies.
 * The dropped pennies will be deducted from the total; however, the deduction will always be 1 more than the total number of pennies dropped. Because of this, donating dropped pennies back into the Donation Machine generally results in a net decrease in the machine's total.
 * causes pennies to instead spawn as double pennies, allowing you to circumvent the above.
 * now only has a chance to turn pennies into double pennies, making the above method no longer guaranteed to work.
 * The Donation Machine will drop coins even when the Donation Machine is jammed.
 * The Donation Machine can be bombed until the coin counter displays zero. At this point, no more coins will drop.
 * A total of 999 coins can be donated to the Donation Machine.
 * If Isaac attempts to donate a 1000th coin, the Donation Machine will explode, resetting its total to 0 and dropping roughly 12 dimes.
 * Donations have a small chance to increase Isaac's luck by 1.
 * Donating ten coins to a Donation Machine will increase the odds of an Angel Room appearing on the current floor.
 * Donation Machines cannot appear while achievements are disabled.

Donation chances
Below is a table of the expected probabilities that donating any amount of coins will jam the Donation Machine, assuming that every donation has an independent 5% chance to cause a jam.

Strategy

 * Causing the Donation Machine to explode at 1000 cents is not recommended, as it does not unlock anything and removes the ability to trade bombs for coins in future runs until the coin total has been rebuilt back up.
 * It is recommended to deliberately bomb the Donation Machine such that the banked total is less than 999 cents. This will effectively prevent accidental 1000th cent donations.
 * With the, every cent received from bombing the Donation Machine is doubled; however, the amount deducted from the Donation Machine is mostly less than what is dropped from it. The profit can be used to buy shop items or donate back to the machine until it jams.
 * Because Humbling Bundle no longer guarantees that every penny is doubled, this method is less effective and can possibly lead to a loss of money.
 * With the, a Blood Bank or , and a lot of patience, enough money can be generated to jam the machine.
 * The Donation Machine can be quickly filled using and farming coins on the first few floors. When the machine jams, simply reset and farm some more.
 * Assuming the player has enough skill, is excellent for filling the machine. Not only can he clear out rooms faster due to his triple shot and above-average damage, he also starts with, Store Key, an extra coin provided that you have the required marks completed, and a bomb that can give you access to out-of-reach coins or possible coins in vases, corpses, and slot machines.
 * If the has Swallowed Penny, this will make surviving easier and grant you unlimited coins.
 * An even easier method to quickly fill up the machine, though it will take a while to unlock, is to use . Almost every enemy drops a coin (which vanishes quickly) when killed. Tainted Keeper has greater damage than normal Keeper, allowing him to quickly 'shotgun' weaker enemies down. Clear out the first floor, picking up as many coins as possible, head to the shop without buying anything, donate as much as possible then restart the run.
 * It is reasonably likely though that the player will have already reached 999 coins in their machine by the time is unlocked. Even still, this is a good strategy for refilling the machine for the benefit of other characters.
 * Force Quit Method. This is an easy way to fill up the machine potentially in one run. This method also has no item prerequisite. The game saves the normal and Greed Donation Machine data separately from your main save file; the machine data is only changed and saved AFTER you leave the room. (Does not work on Afterbirth †)
 * Enter a room with the Donation Machine. Then exit to the start menu normally to save your game.
 * Continue the game.
 * Donate money until machine jams or you run out of coins.
 * Walk out to a different room. Now the game will save the change in coins only.
 * On computer, you will not need to leave the room but will need to suspend the game using an application such as Process Explorer (for Windows)
 * Force quit the game
 * Windows: Alt+F4
 * OS X: Force Quit
 * Linux: Ctrl+Alt+Esc (may depend on desktop environment)
 * Consoles: home button and then quit app
 * Nintendo Switch: eject and reinsert the cartridge
 * Restart and continue the game. Your save game from the 1st step will be restored. It should look the same as before: the Donation Machine is unjammed, but the starting coin count on the Donation Machine is now higher.
 * Donate money. Walk to different room. Force Quit. Repeat.
 * Notes: If you accidentally walk by the machine at 999 coins and blow it up by accident, do not leave the room and just Force Quit. The machine will be back at 999.
 * Despite the 5% jam chance noted above, in actuality, the number of coins it takes to jam a machine is set per floor. Let's say it takes 10 coins to jam the machine. If you Force Quit and try again, it will still take 10 coins to jam the machine even with the higher coin count. When you go to the next floor, let's say it now takes 20 coins to jam the machine. Force quitting on the next floor will still take 20 coins to jam the machine next time. The method works best on a Donation Machine that accepts a large number of coins before jamming.
 * will un-jam the machine and return your coins to you, but the coins you donated will remain in the machine. There are multiple item combinations that allow the player to donate indefinitely:
 * Buying the Glowing Hourglass from the Shop and donating any remaining coins (re-purchasing the Glowing Hourglass refills its charges).
 * Using the will return the ? Card, allowing infinite uses of the Glowing Hourglass.
 * Purchasing (or otherwise acquiring) a Lil' Battery in the Shop while donating.
 * Using the (or the  and two bombs) with more than two hearts.
 * If the Shop has a Lil' Battery for sale, you can donate money, use the Glowing Hourglass to leave the room, re-enter, and charge it with the Lil' Battery endlessly.
 * Due to exploit potential, the Donation Machine can be very beneficial to fragile characters such as and . It may be useful to have a large donation total before starting runs as these characters, since starting a run with an item that grants explosive shots such as, , and  will allow you to endlessly withdraw coins from the machine until it reaches 0. This can allow game breaking strategies to guarantee success, especially with the  and Jera rune. Some of these strategies can be used to spawn Dad's Key as well, eliminating the need for tedious Angel Room farming for key piece s, since the item can open Me ga Satan's door.
 * As of Booster Pack #5, this no longer works, as the Glowing Hourglass now returns donated coins without the donated amount staying in the machine.