While there is no difficulty setting for individual bots, each bot has a distinct style of playing.
All maps have the following bots available:
- Marg Loughbot
- C. Huntingbot
- Jane Stanbot
Some maps have an extra bot available:
- USA (no expansions): Vanderbot Jr.
- Europe: PoirBot
- Swiss: EscherBot
- Asia: KwaiBot
- India: BreretonBot
In general, most players will find the bots at the top of this list easier, and the subsequent bots harder.
Marg Loughbot is typically the least aggressive, as well as being the most lax about completing destination tickets. Near the end of a game, this bot will occasionally draw cards over and over to the point of absurdity, instead of claiming a final route to finish the game.
C. Huntingbot seems to be the most aggressive out of the default three, drawing cards and quickly claiming routes.
Jane Stanbot will usually draw and hold cards, and then claim several routes to more efficiently complete destination tickets.
Vanderbot Jr. will almost always draw a large number of cards early on, and claim several long routes in succession to finish the game quickly. (Beating four of these bots in one game will earn you the
Railway Tycoon achievement.)
The only real source for this information comes from these threads: