Last updated: April 18th 2014
In the market screen you will have the opportunity to purchase gems. Gems have a number of uses in One Dungeon ranging from reviving yourself after losing a dungeon, to replenishing your stamina. You can also use the gem machine in exchange for 5 gems for a chance at a super rare monster.
The gem machine allows you to exchange 5 gems for a chance at a super rare monster, but absolutely guarantees a good monster. There is no limit to the amount of times you can use the gem machine.
The coin machine allows you to exchange 500 coins for a monster. The monsters gained from this machine are not as rare as ones from the gem machine, but can be useful for fusing your monsters.