The Mortar Team is a premium unit that costs 6 and is unlocked at level 6 and requires a Level 2 Barracks.
The Mortar Team is the first unit available to the player that offers splash damage. It is a useful choice as it sports high range and decent splash damage, but as the player levels up and unlocks the Aries, Light Artillery, the Mortar Truck, and the Heavy Artillery, the Mortar Team will become less useful and eventually obsolete. Balancing this out however is its lesser cost of upgrading compared to those units, as well as its relatively low UV in PvP.
The splash damage can be useful to kill off enemies who have low health without wasting multiple turns and as Explosive damage, the Mortar Team is fairly adept at dealing with armored units. Through a mission, one will receive a Mortar Team for free early in the game.
Mortar Teams are also useful due to being able to suppress enemy units, decreasing the enemy's offensive capabilities as a result. As players level up the Mortar Team, it gains access to Frag Shells which switch damage from Explosive to Piercing with increased accuracy, making it more effective against Infantry and Fast Vehicles, but less effective against , which tends to reduce damage. If players are facing enemies without , such as early to mid level Raiders, then Frag Shells would be much more useful. At Rank 5, a second ability slot is granted, allowing both types of shells to be equipped.