For the first time in the series, players are able to synthesise items during battle using the Battle Mix and Extra Mix options. The Battle Mix focuses on enhancing weapons or changing the battlefield; for example, players can add a fire element to their weapon, or melt away surrounding ice. Extra Mix, meanwhile, lets players combine pre-synthesised items to produce greater or new effects; for example, a Bomb can be changed into an Emormous Bomb.
Atelier Lydie & Suelle also allows up to eight allies to participate in combat, with each of the four primary members teaming up with another using the Combination Battle mechanic. While the front member will focus on the combat as usual, the other will hang back, jumping in to defend or support if required.
Atelier Lydie & Suelle will be released for PC, PlayStation 4, and Nintendo Switch in North America on March 27, 2018, and in Europe on March 30, 2018. The third title in the Mysterious subseries following Atelier Sophie and Atelier Firis, Atelier Lydie & Suelle follows twin sisters who discover that they can enter worlds held within paintings.