What principle should I choose? Can I change them?

Historically, Principles were used to power Inner-Magic spells for use in realm-changing roleplay activity, such as that which occurred in the Adventure Log.

Further development of MagicDuel led to the existence of creature-tokens. Some of these are able to give creature boosts depending on the attacker's and defender's principle values.

It is not currently possible to change an existing principle that has already been chosen, unless one descends a Mind-Power (commonly, from MP7 to MP5, or MP6 to MP5). In this case, the last chosen principles will be removed.

It is possible, however, to gain principle points in a principle already chosen, and these are usually gained from sacrificing creatures with heat-scars on them.