Tsai's cartoons and comics demonstrate a great diversity of content. Early in his career he created spoofs such as Drunken Knight. In his middle period he delved into the realm of Chinese classics, both novels and non-fiction. And in recent years, he has become fascinated with math and physics and will soon be releasing what he describes as a "series of major engineering works" -comic books about calculus and physics.
蔡志忠的漫畫題材非常多元，早期的《大醉俠》戲謔嘲諷，中期進入中國古代經典思想和傳奇小說的領域，近年他迷上數學、物理，將陸續推出漫畫微積分、漫畫物理等大工程作品。