Train Troops by Leadership and Level is a mod that allows you to play the game in a different way. It changes how XP is gained and spent in the game, allowing you to train troops and gain levels even when playing offline. The only downside is that this mod requires you to use the game's built-in server to play.

The mod adds a new attribute to the units in the game: leadership. This new attribute is used to calculate how much experience each unit receives when they're trained. In other words, the higher the leadership, the more experience each unit receives.

As you level up, you'll be able to train stronger and stronger troops. This means that as you train your troops, they'll get more experience and will improve in strength.