Galaxy of Heroes allows players to collect Star Wars characters from both the main canonical universe established after Lucasfilm was acquired by The Walt Disney Company and the Legends-canon Star Wars: Knights of the Old Republic series, create teams with them, and use them to fight in turn-based battles. There are multiple ways to collect characters: some are given to players immediately, whereas others are gained via game play or as in-game rewards in the form of shards that are earned by players to unlock and or promote their characters. Shards can either be earned from battles or bought from a shop. Maximizing one non-event character's rarity to seven stars unlocks a special shop in which excess shards from seven-star non-event heroes can be exchanged for gear. The shard amount needed for the character to be unlocked will also correspond to their starting star level, which can range from one to seven stars. Characters can be promoted to a max of seven stars with each additional star increasing their power. There are also training droids that can provide varying levels of experience points to level up characters. Gear, mods, and ability parts can all upgrade characters, although some gear can primarily be won only from battles for one particular side of the Force, to encourage players to play on both sides. The maximum level cap in Star Wars: Galaxy of Heroes is 85, which was changed from the previous level cap of 80 (previously 70). The maximum gear level is gear 13; beyond this, characters improve their "Mastery" with Relic Amplifiers, which have a maximum of level 8 (previously 7). Players level up their user level by gaining experience by completing daily quests or completing battles. The main currencies of the game are "credits" and "crystals". Credits can be used to train a hero, buy things from the store, obtain a hero when you have enough shards or promote a hero's star rarity. Crystals can be used to buy packs from the store, buy credits, acquire character shards, and energy and arena attempt refreshes. Crystals can be bought with money or can be earned as rewards from arena and daily challenges.

Battles are divided up into rounds, with the character with the highest speed stat going first. Each team consists of up to five (six with an ally or summoned unit) different hologram avatars which battle until defeated or retreated. Battles are turn-based, again based on the speed attribute, where the combatants apply various buffs to their own team and inflict debuffs on the opponent all the while trying to deal the most overall damage and have the last character alive.