Gatefall is a strategic miniature game of tactics, deckbuilding and resources.

In the game, a rift has opened between worlds, causing a war between very different types of characters. The basic game mode is designed for two players to compete against each other. Arena mode allows 2-8 players to fight against each other in a Battle Royale setting. In a two-player game, players choose which team they want to control, the fantasy team consisting of Brog, Gildri, and Randar, or the Wasteland team consisting of Exile, Firebug, Penny, and Lost Boy.

At the start of the game, each player has the same pile of ten cards, which contain seven "1" cards and three "0" cards. The first player draws five cards and adds the total of their values. That number represents the number of actions the player can use for his team. You can move or attack one space as an action. These actions can be spread across the entire team or used by just one character, depending on the character's attributes.

During an attack, the attacking player rolls the number of dice corresponding to the attacking character's attack stats. The defending player rolls the number of dice equal to the defending character's defense dice. The number of red rolls is added up and the defender takes damage equal to the number of red rolls the attacking character rolls over his defending roll total. Each player then adds up the number of green dice they rolled and earns one coin for each green die.

Coins are saved and used to purchase new weapons from the weapons market, to destroy "zero" cards in their hands, to buy better cards or to upgrade their individual character stats. Each character has different upgrades. Players can choose one of the available stats to upgrade for each of their characters, and spend the appropriate number of tokens to get those upgrades. When a character is fully upgraded, that character unlocks their special power, which is unique to each character.

When a character is killed, the player who killed that character earns the number of victory points printed on the character's upgrade card, and the player whose character was killed draws a "zero" card from the "zeros" for each victory point, stack on the killed character's upgrade card and add it to their discard pile. The killed character immediately revives, but that character cannot move or attack on the next turn and loses a turn while being revived.

The first player to reach ten victory points wins the game.