First of all, you need to choose a Character in order to begin your quest. Each character has its own strength and weakness in terms of offense and defense.
Once you have chose a character, you can now start to explore the dungeon. As you explore the dungeon, you may come across monsters, shop, gate and links to other dungeon.
You may setup your character by putting up weapons, armor and accessory to improve the character's strength. You could obtain these items from Shops or from killing monsters in the dungeon.
You can also attack other players and grab some item from them on each successful attack.