Book of Demons is a Hack & Slash in which YOU decide the length of quests. Wield magic cards instead of weapons and slay the armies of darkness in the dungeons below the Old Cathedral. Save the terror-stricken Paperverse from the clutches of the Archdemon himself!
The core of the gameplay revolves around a unique card-based combat system. Instead of traditional weapons and gear, players acquire and equip various ability cards to build their character's loadout. These cards represent spells, items, and equipment like armor and trinkets. Each of the three playable classes - Warrior, Mage, and Rogue - has its own distinct set of cards that offer different playstyles and abilities.
One standout feature is the Flexiscope system, which allows players to choose the length of each gameplay session. The game generates procedurally-built dungeons that can fit playtime constraints, ranging from very short 8-minute runs to longer 40-minute expeditions. This caters to players with varying schedules, enabling them to make meaningful progress even in short bursts. The Flexiscope system also adjusts the loot, enemies, and difficulty accordingly, ensuring that shorter and longer sessions are equally rewarding.
The combat system places a greater emphasis on maneuvering, managing resources like health and mana, and executing the right abilities at the right time. Players can move their character along a grid-based path, but cannot freely click-attack enemies. Instead, they must time their card activations carefully to avoid enemy attacks and capitalize on moments of vulnerability. Enemies with diverse abilities, such as shields, summoners, and projectiles, force players to adapt their strategies on the fly.
The procedurally generated dungeons ensure that each playthrough offers a unique experience, with randomized layouts, enemy encounters, and loot. The game's freeplay mode and higher difficulty settings further extend the replayability by introducing new challenges and obstacles to overcome. As players progress, they can unlock more powerful cards and gear to tackle increasingly demanding dungeon runs.
Various quality of life features, such as automatic gold and item pickup, footprint trails, objective indicators, and quick teleportation, contribute to a smoother and more comfortable gameplay flow, reducing frustration and allowing players to focus on the core combat and deckbuilding mechanics.