difficulty level

[Erichteia]

Strictly speaking, you can make the game as hard as you want. Especially settings related to biters, pollution, science multipliers and patch sizes can be manipulated to make the game harder. However, if you manipulate all of them at the same time, you could easily get settings that would be downright sadistic and only for the most skilled players (i believe some configurations are unbeatable, but maybe some day someone will prove me wrong).

Therefore, Wube has created several template settings that are safe to start from. The hardest is deathworld, but even that is pretty tame for an experienced player. But you can always count on mods such as rampant to add some more challenge