Adventure Time: Card Wars is a paid iOS app with Free-To-Play-like micro transactions. The player plays as the cast of Cartoon Network's Adventure Time in a 1 on 1 fictional turn-based card game, similar to Magic: The Gathering or Hearthstone. The game is $3.99 on the iTunes Store or Google Play service.
Each player starts with a deck of cards that are comprised of creatures, spells, buildings, and land. The gameboard is divided into 8 slices of land, 4 slices per player. Each player uses any combination of 4 land cards and declares the land type of each slice. The land type determines what kind of creature you can play, ie cornfield, blue grass, sandy desert, etc. In general, creatures of a certain land type appeal to certain play styles; sandy type creatures have high attack ratings but low defense, while sweet land creatures have low attack ratings but specialize in healing abilities. After land is declared, a spinner randomly determines which player goes first.
The gameboard is divided into 8 slices, where each player places creatures and buildings.
At the start of the turn, a player gains a small amount of mana points to spend. Players may stockpile up to 10 mana points. Summoning a creature, building, or casting a spell requires mana. Additionally, activating a creature ability costs mana. Each creature occupies one slice of land, for a maximum of four creatures per player. After a player ends their turn, their creatures attack (with the one-time exception of the very first turn, so that the opposing player has a chance to defend themselves). Creatures attack in a straight line only, against the opposite slice--these two opposing slices are referred to as "lanes". If there is no creature to block the attack, the damage is dealt directly to the player's life. Like Magic: The Gathering, The game is over when a player's life reaches zero. Creatures may be buffed by summoning a building on a slice of land behind a creature. Buildings are ignored by creatures but may be destroyed using spells. Spells may be used during a player's turn, and have all sorts of various effects including destroying creatures, gaining mana, drawing more cards, etc.
Lastly, each player has access to a "global" ability that has a long cooldown. The global ability is unique to each hero or cast-character unlocked by the player. For example, using Finn the Human's ability adds 2 extra mana points that turn.
The game is played in either a singleplayer "quest" mode where players progress through a path on a map. Each node on a map is a challenge by a CPU-controlled opponent. By progressing through this mode, the player can gain coins, hero cards to play as different characters, find common cards, and find card recipes for crafting. Lastly, experience points are gained for winning, and when enough are accrued a hero card gains a level. Gaining levels allows the player to have a larger deck, and the hero card gains maximum life points.
The other mode is called "Deck Wars" and this serves as the game's quasi-multiplayer mode. The player is entered into a two-week long tournament, where all players are partitioned into brackets of 100 similarly-leveled players. The player may challenge other players, but the opponent is merely a CPU-controlled opponent using the deck customized by the player. Conversely, other players in the bracket may challenge the player's deck. Winning a game awards the victor with 4 trophies, with unbroken winning streaks awarding more and more trophies. Losing a game provides 1 consolatory trophy. A player may accrue trophies without actually playing a game if their deck wins a challenge against another player. The player with the most trophies by the end of the tournament is the winner. Rewards are distributed to the players in the tournament, with better rewards going towards players closest to first place. The first place prize is a super-rare card from a "black chest".
The game has a few different resources carefully designed to extract as much money from players as possible. The single-most important resource is gems, which can be purchased with real money in in-app purchase bundles, similar to Plants Vs Zombies 2. The player can spend gems to buy 1 random rare card. These rare cards are generally much more powerful than cards one would acquire throughout the campaign.
The easiest way to get more gems is to buy them, however a single gem can be had if the player gets 3 stars in the singleplayer campaign. In order to get 3 stars, a single stage has to be beaten 3 times, each time with a special condition such as "Without using spells" or "Cornfield creatures only". The game comes installed with 5 gems in stock. Lastly, gems can be acquired in the game's semi-multiplayer mode Deck Wars for placing within 11th to 25th place in the tournament bracket.
Coins are the secondary currency that are acquired through playing the game. When a non-CPU player wins a round, they are rewarded with a few hundred coins. Coins are used to craft new cards, or if a player somehow manage to stockpile 10,000 of them, he or she can buy a semi-rare card.
Then there's the "heart energy" which is a currency used to play each game. In the singleplayer campaign, each game costs 1 heart, but eventually this toll increases as you progress. If the player runs out of hearts, they may spend a gem to restore heart energy. Heart energy automatically restores slowly over time, or if the hero-character gains a level.
If the round is lost, the player may spend gems to recoup any cards or coins found that round. Otherwise, any cards and coins found that game are forfeited.