The objective is to destroy your opponent's crystals using heroes and spells before they can destroy yours. It is important before you begin a match that you take a moment to review the crystal placement, as their arrangements will determine the strategy you employ. Sometimes as well as crystals there will be things like destructable terrain, buffs, and power tiles on the game board which you will need to take account of as they can influence a match.
You begin a match on opposing sides of the game board with a summoning area which is the zone you place heroes and defend crystals against enemy attacks. Additional summoning areas become unlocked when you destroy your opponents crystal. Each hero has two moves (actions points that are indicated by green orbs) that you can use when it's your turn and once you use one to attack your hero's turn will end so it is important to move first so you are able to take advantage of your action points. You can have up to 5 heroes on the game board at any one time so you need to think strategically before you summon them.