Roith earned a two-year PDC tour card in January 2012 on the fourth and final day of the Qualifying School with a 6–5 win over Les Wallace in his final match. He represented Germany with Jyhan Artut in the 2012 World Cup of Darts and together they were beaten 3–1 by the United States in the second round. In June, he earned a place in the German Darts Championship in Berlin by defeating Sven Mehl and Tomas Seyler in the Home Nation Qualifier. Roith played three-time world champion John Part in the first round and was beaten 6–1. In October, Roith beat Lars Erkelenz and Michael Rosenauer in the European Qualifier for the Dutch Darts Masters, but was whitewashed 6–0 by Vincent van der Voort in the first round. In an attempt to reach the 2013 World Championship, Roith lost in the quarter-finals of the Qualifier 5–3 to Stuart Kellett.