A Ball of Moss was, prior to the release of the vanilla enchantment Mending, an item that added a modifier (called "Mossy") for both tools and weapons. The ball of moss is still used in more recent versions of Tinker's Construct, but its function is different, as described below. The Mossy modifier slowly repairs items over time. The Mossy modifier stacks with itself, and the rate of repair is multiplied directly by the level of Mossy on the weapon or tool. Each level of Mossy requires its own modifier.
After the release of the Mending Enchantment, the Mossy modifier was reworked, but the Ball of Moss continues to exist. The Ball of Moss can no longer be applied directly to a tool to add the Mossy modifier; instead, its only use is in the creation of Mending Moss. Mending Moss is obtained by right-clicking a bookshelf with a Ball of Moss in-hand while the player has at least 10 levels. This will remove 10 levels from the player and convent the Ball of Moss into Mending Moss. Mending Moss can be applied to a tool to give the tool the Mending modifier. The Mending modifier causes the weapon or tool to gain a buffer of 100 experience points (not levels) at Mending I. If the buffer isn't full, the modifier will absorb experience points that would be gained by a player holding the tool in either hand, and put them into the buffer. If the tool is at less than 100% durability, and there is at least one experience point in the buffer, the Mending modifier will spend a small amount of the experience to repair some of the tool's durability. Increasing the level of Mending (by applying additional Mending Moss and consuming additional modifiers) will increase the size of the buffer.
Note that this recipe uses the Forge Ore Dictionary's "blockMossy", meaning you can use any mixture of moss stone, mossy stone bricks, and other, similar blocks.
- The Mossy modifier could be applied to ammunition like Arrows, Bolts, and Shuriken. Doing so would cause the supply of ammunition to increase over time. This behavior may or may not also be true of Mending.
- The rate of repair for Mossy would increase while standing in direct sunlight, while the rate of repair on Mending is instead increased while standing in the rain.