Many years ago, a formidable Darkness overpowered the world. To save humanity, the Old Gods from four mighty tribes joined forces to vanquish this menace. Once victorious, they retreated to their lands, resuming old rivalries. Now, this Darkness has returned, stronger than ever, but the Old Gods remain oblivious to the looming threat. Your mission is to prevent the impending apocalypse by defying the Old Gods and uniting their tribes. This is the tale of the game Idle Monster Frontier - a team RPG inspired by this ancient saga. Your task is to unite the four tribes and combat the Darkness.

A creature from the Outer Realms aids you in your quest against the Darkness, providing you with monsters to form your initial team. Strategically align your monsters to defeat enemies, starting with the strongest and moving to the weakest. An elephant is an excellent choice for your starting monster. Use the travel buttons at the top to send your monster into battle, and tap the upper world area to boost your monster's speed. Defeating enemy monsters may allow them to drop and join your team. If your team members fall, respawn them at your home base. As you progress, levels become more challenging, so upgrade your monsters with the gold you collect.

Monsters can also be enhanced with traits, each possessing a core trait that is irreplaceable. To acquire traits from other monsters, use the learn button and sacrifice the contributing monster. Capturing and eliminating wild monsters to learn their rare traits can be more crucial than merely leveling up. Assemble a powerful team with formidable monsters. To create a superior monster, merge two strong ones. A sparkly marker at the top of your screen indicates the Frontier, the most distant conquered outpost. Battling on the Frontier is more challenging, with fiercer monsters. To complete a level, reach the end of the outpost; once claimed, you can teleport to the furthest outpost from your home base. Your ultimate goal is to save the world from the Darkness.