Keys are used to open treasure chests or rooms that are locked. A key can be used when a triangular sign which is glowing green, yellow or black, with a key-shaped symbol in the center, is seen. The player's inventory has a capacity of 5 pieces per kind and they cannot be sold or discarded .
Small Key Edit
Starting price (at rebirth 1): 2,500
Cumulative gain per rebirth: 500
Small keys are green in color and unlocks chests which contains common items, low gems or gold slightly more than the current cost of the key. They can be bought, received from chests, won from battles, or sometimes simply lying around.
Medium Key Edit
Starting price (at rebirth 1): 5
Cumulative gain per rebirth: 1,000
Medium keys are yellow in color and unlocks chests which contain items that are of greater amount than those which can be gotten from small key unlocked chests. They aren't usually seen lying around but they can be dropped by stronger enemies.
Large Key Edit
Starting price (at rebirth 1): 100,000
Cumulative gain per rebirth: 5,000
Large keys are black in color. It can be used to unlock five black treasure chests which can be found near where the three blood sentinels are located, near the Worker of Secrets, and at the bottom of Saydhi's staircase. It also unlocks a room located before the top of the tower, where there are bookshelves. This room leads to the three enemies imprisoned by the Deathless. The treasure chests can contain either rare items or a large amount of money. It can initially be bought at the store for 100,000 gold pieces. It looks like a regular key except one end is in a circle which has seven rays, the eight being the key itself. They can only be dropped by extremely difficult Titans or by a Deathless.
The first time you defeat the MX-Goliath, you will receive a large key.
Infinity Blade IIIEdit
Small key starting price: 40 chips
Medium key starting price: 150 chips
Large key starting price: 450 chips