Under the Darkening Sun code system, spell casting classes have a much greater control over what spells they learn. No longer is a class guaranteed that he will gain a certain spell simply by gaining a level. Now, each spell caster chooses different spell Spheres and Realms that dictate what spells will be available during their character's life. As you gain experience, other spheres and realms can be gained to increase your character's spell casting ability.
Another point of interest is that the time of month and year affects a mages' and spellfilchers' casting ablities.
There are 3 ways you can gain a spell:
1.Teaching - A spell can be taught to you by another player who already knows the spell. This method has the greatest chance of success.
2.Studying - You can learn a spell by studying it from a scroll.
3.Levelling - When you level a series of random checks are made to see if you learn a new spell. The higher your level and the higher percentage you have all the realms and spheres for a certain spell practised, the better chance you have of learning it. Technically, it is possible for a second level mage to learn a high level spell like frostball, but that would be a rare case indeed! (about 1 in 100,000)