Magic: The Gathering – Tactics is a turn-based strategy game, in which the player must defeat the opponent's army. The player controls a Planeswalker, and an army in the form of a deck of cards. The player starts with a starter deck, and can obtain more cards by trading them in an auction house, or by buying them in a cash shop. Gameplay differs from the card game in that instead of having land cards, which supply energy, the player automaticly has a pool of energy depending on the cards in their deck. The player's Planeswalker is able to level up, which allows them to change their looks, add space to the deck, and specialize in talents.
Source: Wikipedia, "Magic: The Gathering - Tactics", available under the CC-BY-SA License.