Hwang had initially written the series as eight episodes, which was comparable to other Netflix shows, but found that the material for the last episode was longer than he planned, so it was split into two.
The use of this familiar character was meant to juxtapose memories of childhood and unsettling fear in the players.
For example, Ali Player 199 is shown in the second episode to be tricked by his employer out of his wages, while his death comes after he is tricked into giving Sang-woo his marbles in the sixth episode.