NHF – new heroes for Heroes V 3.1.

That's interesting; I've had it happen twice where I got 3 spells: on levels 5-6, 15-16, and 20+.

But even so, if you distribute them by level, you can approach it tactically, otherwise, you just have to rely on luck.

We could set a maximum and minimum drop rate, like with the incorporeality of ghosts (where you're guaranteed to get it on the 4th try). If it doesn't drop several times, it will definitely drop on the next try, and vice versa, thereby reducing the uncertainty, i.e., the influence of luck. ;)
Thanks, I'll do that.