How do I increase my principles?

[Else]

How do I increase my chosen principles?

[Lazarus]

The only way that I know of is by sacrificing your creatures to various Altars scattered throughout MD. Of course, the value of the principles that can be had is dependent on several factors about the creature you want to sacrifice such as age, level, win counts and whether or not they have tokens on them.

[Dracoloth]

The main way to increase principles is by sacrificing creatures at sacrifice altars.

[Muratus del Mur]

Except altars, there are several clickables and places that offer you this opportunity, The basket on the Gateway Island Mountain is one of these.