- A reference guide and manual in Russian for Heroes 3.

Specialization is an interesting topic, but it requires a lot of time for "research," unfortunately... :) If I get the chance to work on it, I'll add it.

If you're interested, I can explain how unit specializations work.
1. A unit specialist adds +1 to the speed of that unit.
2. It adds +1 to the attack and defense at the level of the specialist's creature. It adds 5% to the attack/defense when the hero reaches level X*Y, where X is the level of the specialist creature, and Y is an integer (Y=1, 2, 3...).
For example, a skeleton specialist adds +1 to attack/defense at level 1 and 5% for each of their levels, starting from the second. A vampire specialist adds +1 to attack/defense at level 4 and 5% at levels 8, 12, 16, 20, 24... A cavalry specialist adds +1 to attack/defense at level 6 and 5% at levels 12, 18, 24... Moreover, the bonus is rounded up if the next 5% bonus causes the bonus value to cross an integer (e.g., if the current bonus is 1.8, and the next one will be 2.2), and rounded down if there is no such transition (e.g., if the current bonus is 1.8, and the next one will be <=2).