Secondary skills in Heroes 3.

A good online hero should develop, I think, into a "battle mage," based on a level 1 fighter with a predominance of fighter skills in approximately a 50% to 25% magic and 25% general skills ratio. Fighter skills include, of course, Offense, Armor, Tactics, and Archery (although it's not essential for all castles). Magic skills primarily consist of the super-combination of Earth and Wisdom, but if, for example, there's no emphasis on archery and slowing down targets, and instead, the goal is to engage in close combat as quickly as possible, then Air is an excellent alternative; in some cases, Water and even Fire can also work; if there's a focus on offensive spells, then Magic can also be taken. General skills primarily refer to Logistics – it's unmatched among these skills; depending on the circumstances, Leadership, Pathfinding (if you're exploring penalty respawn areas from the first week), Training (although it's not often taken), Resistance (if the opponent has a powerful mage leading their forces), and even Luck can be useful (if, for example, the alternative would be Navigation or Eagle Eye). For less experienced players, Property and Scouting can also be quite effective; Logistics, if possible (e.g., through a witch's hut), should be taken by everyone! This is just my humble opinion, and I'm still a beginner...