Sword of the Necromancer is a dungeon-crawler action RPG that combines Rogue-like elements with a unique gameplay mechanic of reviving defeated enemies. Players assume the role of Tama, who ventures into a perilous dungeon to seek the power to resurrect her fallen companion, Koko. With the ability to turn foes into allies using the eponymous Sword of the Necromancer, players can build a small army of monsters to aid them in their quest.

The game features a procedural weapon generation system, allowing for diverse combat experiences through various weapons and relics. As players progress, they can enhance their character and summoned monsters, while the local co-op play option enables shared adventures with a friend. Each attempt brings players closer to their goal, with a unique death mechanic that retains half of the player's level, ensuring that each run contributes to their overall progression in the game.