These sequences are also known as "cubefree," so you might want to continue researching along those lines. In particular, the game discussed is trying to find

These sequences are also known as "cubefree," so you might want to continue researching along those lines. In particular, the game discussed is trying to find cubefree words over a two-letter alphabet. The sample infinite game seems to agree with the listed sequence on OEIS for the lexicographically earliest infinite cubefree word, though your method of generation appears to be different from the one in the comments. (I haven't analyzed it in detail.) https://oeis.org/A282317 https://oeis.org/A282317