Bound by Flame is an action RPG set in a fantasy universe. The player controls the mercenary Vulcan who protects the lands against a siege by the seven ice lords and their minions. He starts as an experienced fighter in the game, but early on he messes up summoning a fire demon and instead becomes possessed by it. This introduces a duality that forms the backbone of the game, as he can either attempt to restore his humanity or give in to the possession and embrace the powers. This change is guided through his actions, either helping villagers or working against them, and not only leads to visual change - either restoring the human form or slowly transforming into a fiery demon - but also to branching story paths with multiple endings.
The game offers three skills trees: fighter, ranger, and pyromancer. Each path has its own abilities. The fighter path stresses melee combat, while the ranger introduces stealthy gameplay and magic spells. The pyromancer delves into fire powers, offering various spells, explosives, and weapons enhanced with fire. The skills are divided into four tiers: novice, amateur, expert, and master, narrowing the choices with each new tier. All of the paths lead to an ultimate ability. While fighting, it's possible to switch stances between warrior and rogue. The game also features companions and weapon crafting with various modifiers.
The game world is divided into smaller hubs, one for each chapter, offering freedom to explore and complete quests in any order until the entire hub is done, then moving on to the next chapter. A mini-map helps navigate areas at the bottom right corner.