Fortune

Fortune is an enchantment applied to mining and digging tools to increase block drops.

Usage
For coal, diamond, emerald, nether quartz, and lapis lazuli, level I gives a 33% chance to multiply drops by 2 (averaging 33% increase), level II gives a chance to multiply drops by 2 or 3 (25% chance each, averaging 75% increase), and level III gives a chance to multiply drops by 2, 3, or 4 (20% chance each, averaging 120% increase). 1 drop has a weight of 2, and each number of extra drops has a weight of 1.

For redstone, carrots, glowstone, sea lanterns, melons, nether wart, potatoes, beetroots (seeds only) and wheat (seeds only), each level increases the drop maximum by +1 (maximum 4 for glowstone, 5 for sea lanterns, and 9 for melon slices).

For tall grass, each level increases the drop maximum by +2.

Fortune increases the probability of flint dropping from gravel, and saplings dropping from leaves, and apples dropping from oak and dark oak leaves.

If commands are used to give an item an extremely high level of fortune, mining a block will make it drop an excessive amount of ore that can cause copious amounts of lag.

Incompatibilities
Silk Touch and Fortune are mutually exclusive. If commands are used to apply both Silk Touch and Fortune to an item, the Silk Touch enchantment will take precedence over the Fortune enchantment for blocks affected by both enchantments.