There are currently 5 elements in MinoMonsters. They are Fire, Water, Air, Electric (Lightning) and Ground (Earth). Fire is good against Ground (Earth), but weak to Water. Water is good against Fire, but weak to Air. Air is good against water, but weak to Electric (Lightning). Finally, Ground (Earth) is strong against Electric (Lightning), but weak to Fire. One odd exception is Fire damage is powerful against earth Gurblings.
Those type advantages are vital later in the game to advance past boss stages. Remember that Powerful/Weak pairings are not reversible. That is to say although water is powerful versus fire, using a fire attack versus a water monster will still yield regular damage as opposed to weak damage. The full pairings of type advantages and weakness are below:
*note: resistance have since been removed from the game