Atelier Shallie: Alchemists of the Dusk Sea is the sixteenth game in the Atelier series and the third game in the Dusk subseries. The game takes place six years after the beginning of Atelier Escha & Logy: Alchemists of the Dusk Sky and ten years after the start of Atelier Ayesha: The Alchemist of Dusk . The world has become a harsh place where two very different alchemists, Shallistera (Shallie) and Shallotte Elminus (also Shallie), meet at an oasis town where the water sources dry up. Shallotte tries to make ends meet to support her mother, while Shallistera focuses on saving the village.
The gameplay is similar to other Atelier games but with a greater focus on life tasks and quests rather than time management. The player chooses one of the two alchemists and completes specific tasks for the Stellade merchants' association, which can be freely explored to gather items and harvest raw materials.
The gameplay is also different from previous Atelier games in that the tasks are not always combat-related. Instead, players may receive tasks such as catching fish or cleaning rooms, depending on the chosen character and play style. The fields change dynamically during exploration based on the life tasks.
Items are created through blueprints and ingredients, and can be combined into new ones. The order in which ingredients are selected can also affect the item's properties. As the player progresses through the game, they gain access to a Chain system that influences the effect of skills and can be used during item creation.
The battle system is turn-based with a party of up to six characters. The Burst gauge can be filled by consecutive attacks, allowing players to activate special skills and boost effects through the Chain.