I wrote that code for Fall Flat, so I can tell you how it works... The Amurites count each mana source, not each unique mana source. The chance increases with a Cave of Ancestors, though perhaps not enough. Before I stopped working on Fall Flat, a very low chance for 3rd level spells was in the code, but I think it didn't get passed along into Fall Further. Or that version might not have ever made it to release. I still feel the Amurites are strong, and a lot of it has to do with the kind of mana you focus on. If you get Nature and Enchantment mana, yes, your t2 spells are going to bite big wind. If, however, you get fire, sun, and death mana, you have random swordsmen capable of doing the city siege thing all on their own. I'll be the first to admit getting Nature II on a Longbow or Enchantment II on a Hunter bites big wind, but the reverse of those sucks a lot less. The unit-specificness of those spells sucks but has nothing to do with getting them for free. As a second comment - another option you have for boosting this is very occasionally granting a random unit Channeling I, or Channeling I and II with the Cave, making some units full mages at random. I think this also is neat - represents someone whose magical talents showed up after he was drafted to go poke guys with a sword, and now he can do both. A lot of the random unit gets spell is more nifty than omg incredibly useful, but that's due to the yawn-inducing abilities of many tier 1 spells in a lot of cases. On a neat level, though, sometimes it's handy to have a swordsman who can cast law I running around being able to make your soldiers loyal instead of having to drop a wizard promo on it.