Seek-a-Boo is designed as a treatment-aiding method for autistic adolescents who have learning difficulties. In order to build their learning abilities, the design uses games as a substitute for verbal communication. In the proposed games, autistic adolescents are guided to identify transportation vehicles, thus improving their identification capability through concrete hands-on exercises. Phase 1 – Identifying the building blocks: Traditional building blocks require an initial organising process, which can be difficult for the target group. Seek-a-Boo, however, displays a themed set of blocks on each exterior face of the packaging. This gives the user an initial guide and enables them to identify the functions and shapes of the individual blocks more easily. Phase 2 – Getting started to build something: This design encourages the children to try finishing all designs through appropriate guidance. For example, the transportation vehicles theme boosts the users’ interest, while deepen their impression of real-life vehicles as they see them on a daily basis. The single tenon design also increases combinational diversity and make the blocks simpler to assemble. Phase 3 – Interaction: The design of Seek-a-Boo allows one to four users to simultaneously play with the same set. During the gaming process, multiple autistic children can be guided to interact with those playing with them. Apart from assembling single-themed sets, the players may also exchange parts to create various combinations of the blocks.