Robots

The online version of Ticket to Ride also introduces Robots (also abbreviated as "Bots"). These robots are programs that play like other players. Robots are used for two things:

Training or Solo Games
If you want to practice or play alone against non-human opponents, you can create a table with robots as the other players. Note that in this case, your game will not be ranked.

"Hot Swap" of Defecting Players
If a player leaves the table during a game for one reason or another (network disconnection or defection), he is automatically replaced on-the-fly by a Robot. This way, the game can continue, and the other players are not stuck.
If the player returns quickly, he can take back his seat and resume playing. If he does not come back, the Robot will finish the game, but its performance will be applied to the player's ranking. So if the Robot played badly, this will impact negatively the player's scores...