Beyond Sosaria layers a roster of custom spell systems on top of the standard Ultima Online magic schools. Custom spellbooks and scrolls are issued primarily as boss and town invasion loot.
The custom engine adds the following schools: Magery, Necro, Chivalry, Ninja, Samurai, Druid, Avatar, Bard, Cleric, Ranger, Rogue, Undead, Ancient, and Archmage. Spell restrictions are enforced: casting a custom spell requires the matching spellbook to be equipped, carried in the backpack, or stored inside a Sosarian Tome.
| System | Cast Skill | Damage Skill | Spellbook |
|---|---|---|---|
| Archmage | Magery | Evaluating Intelligence | Archmage Spellbook |
| Avatar | Chivalry | Focus | Avatar Spellbook |
| Bard | Musicianship | Musicianship | Bard Spellbook |
| Cleric | Spirit Speak | Evaluating Intelligence | Cleric Spellbook |
| Druid | Animal Lore | Animal Taming | Druid Spellbook |
| Ranger | Archery | Tactics | Ranger Spellbook |
| Rogue | Stealing | Hiding | Rogue Spellbook |
– Not Currently Accessible.
These schools are active alongside the custom systems.
| School | Cast Skill | Damage Skill | Spellbook |
|---|---|---|---|
| Magery (1st-8th Circle) | Magery | Evaluating Intelligence | Spellbook |
| Necromancy | Necromancy | Spirit Speak | Necromancer Spellbook |
| Chivalry | Chivalry | Chivalry | Book of Chivalry |
| Bushido | Bushido | Bushido | Book of Bushido |
| Ninjitsu | Ninjitsu | Ninjitsu | Book of Ninjitsu |
| Spellweaving | Spellweaving | Spellweaving | Spellweaving Book |
| Mysticism | Mysticism | Imbuing or Focus (whichever is higher) | Mystic Book |
| Skill Masteries | Per-mastery primary skill | Per-mastery skill | Mastery primers / Book of Masteries |
| Gargoyle (Flight) | n/a (racial) | n/a | – |
Spellbook types available: Regular, Necromancer, Paladin, Ninja, Samurai, Arcanist, Mystic, and Skill Masteries.
Custom spellbooks (Archmage, Bard, Cleric, Druid, Ranger, Rogue) drop with a 20% chance from Warlord-class town invasion bosses, with one of the six chosen uniformly at random. Custom books may also be stored inside a Sosarian Tome, which lets spell restrictions resolve against books stowed in the tome instead of the open backpack.