Thirteen (video game)
Thirteen was a Doctor Who video game released exclusively online.
Gameplay
The game is a variant of the popular game "2048". The player must match Doctors to reach a higher numbered incarnation until the Thirteenth Doctor is achieved.
Notes
While in 2048 the end goal is to get the 11th generation of tile (log22048 = 11), in Thirteen the goal is to get the 14th generation of tile (as it includes the War Doctor). It is in principle possible to achieve at most the 17th generation of tile.[1] A study done with artificial intelligence found that the 12th generation of tile is possible in 100% of cases, if played as a computer would, the 13th 99%, and the 14th, what is asked for here, only 92%. The 15th and above have overwhelming drop-off, with only 30% of games played leading to a 15th generation tile.[2]