Lucca is one of the seven main playable characters in Chrono Trigger
Lucca is Crono's best friend. She is a playable character who appears in every episode
Lucca is working on her positional teleporter. After a successful demonstration, Marle wants to try it on herself. Marle's pendant reacts to the machine though, causing a gate to open up and send Marle to the Middle Ages. Crono gives chase.
Lucca catches up to Crono in the Middle Ages. After hearing about Marle's vanashing, Lucca explains that Queen Leene is still in danger, and if she isn't rescue, the entire Guardia Line, including Marle, will cease to exist.
As Crono's party marches to find a gate exit from the future, The party finds a damaged robot. Lucca decides to repairs it. Upon it's awakening, it declares Lucca as its master and joins the party under the name, Robo.
As the party attempts to escape Derelict Factory, six R-Series Robots confront the party. They are the exact models of Robo who call Robo a mistake for losing his "true purpose" After they beat up and trash Robo, Lucca attacks the robots in rage. She repair Robo shortly after.
Lucca decides to pursue a stone with near limitless energy, called the Sun Stone. She retrieves it in the Future, but finds it expired. She takes it to the Sun Shrine in Prehistory and let's it charge, only to find it stolen in the Present by the Porre Mayor. After giving his ancestors free jerky, the Mayor is generous and gives the Sun Stone back. Lucca finally retrieves the charged Sun Stone from the Future, allowing her to create powerful equipment
After retrieving Robo from assisting in the creation of Fiona's Forest, Lucca repairs Robo to get him back to combat shape. In the middle of the night, she sees a light call to her. She finds a gate which takes her to 990 AD in her own home. She finds herself back to the accident where Her Mother got trapped in Taban's machine, causing her to lose her leg's motor ability. Lucca uses Taban's emergency password to stop Taban's Machine and saving her mother's legs. She then returns to the Present where she is comforted by Robo. It is believed that The Entity allowed Lucca the chance to save her mother.