In mechanics it’s pretty simple, there’s the battlefield, there are mana crystals that you put on the field of minions and use abilities.
Minions can deal damage in melee or ranged combat, depending on the creature type.
Your creatures can have the following properties:
Ability – Can do something for X mana once per turn.
Bloodtoll – An additional cost that MUST be paid for play the card.
Bounce – Return to its owner’s hand.
Charm – Forces a unit to move towards the charming a unit or tile.
Charge – Can attack and move on this turn it is summoned.
Choose one – Choose one of the available features.
Damage Shield – Blocks the first damage dealt against this unit.
Deepstrike – Can be summoned to any location on the battlefield.
Deathhowl – Does something when it dies.
Exile – Removed from the game. Prevents Deathhowls and doesn’t enter the graveyard.
Fear – Forces a unit to move away from the fearing unit or tile.
Flying – Can move to any location on the battlefield.
Loyalty – Does something when next to your hero.
Poison – After this unit deals damage to a minion, destroy that minion.
Root – Cannot move.
Splash – Also damages all enemies next to whomever it attacks on its turn.
Stun – Cannot attack, counterattack, move, activate triggered effects, or use abilities.
Supremacy – Does something when on High Ground.
Uncontrollable – Not controlled by anyone, run from these as far as possible.
Upgrade – May choose to pay extra mana to gain ONE of the upgrade options.
Warcry – Does something when you play it from your hand.