LEVEL-UP: The GM rewards a character a level based on Merit. By default, i20™ assumes by campaign milestone and limited by Experiences using Improvement Limits. Multiclassing follows i20 multi-class parameters in addition to the base requirements. Sanity increases by 1 every 4 character levels.
Multiclassing [through game play] follows the i20™ Improvement Limits precepts.
Multiclassing must be reflected in time and resources required to learn the new skills and traits and integrate them seamlessly into their existing classes capabilities. Multiclassing sacrifices depth for breadth of capability. It is assumed a character draws upon a lot of their existing experiences to accelerate the uptake of a new class.Significant time to acquire/achieve outside of Character Inception.
The most applicable requirement of multiclassing is finding a means to learn all required elements to gain a class. A character spending 10 years as a Fighter cannot simply grab a book and be a spell-caster. The time and cost to study and practice are required before any benefits can be acquired. Any time and costs associated with leveling up and multiclassing are the equivalent and longer for for species with a long life thread.