Apple!

Effects

 * Adds a chance to fire razor blades that deal quadruple Isaac's tear damage.
 * The chance to fire a razor blade depends on the luck stat, and goes up to 100% at 14 luck.
 * +0.3 tears.

Interactions

 * : Adds chance for beams to do quadruple damage.
 * : Adds a chance for bombs to do double damage.
 * : Adds a chance for missiles to do quadruple damage.
 * - Needle shots' visuals and damage multiplier are overridden by the razor blades if both occur on the same tear, but retain the instant kill ability.
 * : Adds a chance for knives to do quadruple damage.
 * - Tears can gain the effects of razors, boogers, or both, though the chance for both to occur on the same tear is low. Razor blades visually override boogers in these cases.
 * : Adds a chance for lasers to do quadruple damage.
 * : Overrides Apple!.
 * - Tooth shots are overridden by the razor blades, though at under 14 luck it's possible to get both.

Synergies

 * //: Each tear has an independent chance of being a razor.
 * : When razors are fired, they will hover in the air until the fire button is released.
 * : When razors are fired, the charge time determines size and damage.
 * //: When razors are fired, the split tears will also be razors and do quadruple damage. The Parasite's split tears look like normal tears.
 * : When razors are fired, they bounce against the floor.
 * : Adds a chance to fire a giant razor that does triple damage.
 * : When razors are fired, they will retain all of Godhead's effects.
 * : Adds a chance for tears to do quadruple damage. Burst tears will also do quadruple damage if the main tear does quadruple damage.
 * Homing tears: When razors are fired, they will home in on enemies.
 * : Adds a chance to fire an explosive razor that does quadruple damage.
 * : Adds a chance to fire razors that can be fed and deal quadruple damage. Burst tears will also deal quadruple damage.
 * : Allows you to control a giant red tear that has a chance to do quadruple damage.
 * : Razors will grow in size and damage as they travel.
 * : Tears and razors will be fired in the direction of the crosshair.
 * : Tear barrage increases chances of razors being fired.
 * : When razors are fired, they will return to Isaac.
 * Piercing tears: When razors are fired, they will have the piercing effect.
 * : When razors are fired, they will knock into other tears.
 * : When razors are fired, they will shrink as they travel.
 * : Adds a chance for large spectral razors to be fired.
 * : When razors are fired, they will bounce off walls and obstacles.
 * Spectral tears: Razors become spectral.
 * : When razors are fired, they will connect to other tears via electricity. The electricity also does quadruple damage.
 * : When razors are fired, they will orbit Isaac.

Trivia

 * Both the item itself and the description is a reflection of one of Isaac's nightmares between floors that involves him finding a razor blade inside a piece of candy.
 * The item and pickup quote are a reference to the urban legend of giving away candies with razor blades hidden inside of them as a way of harming people.