Modifying game files.

Overview

I found nice options to improve your game.

Safety

Before doing anything copy the original file.

Unlocking factions

To unlock factions in campaign, find descr_strat (mostly in C:Program Files (x86)SteamsteamappscommonMedieval II Total Wardataworldmapscampaignimperial_campaign).
Open this file and move factions that you want to play from nonplayable and unlockable to
playable.
However sometimes this can cause problems when you try to modify the file twice.

Unlocking factions in historical battles

Navigate to maps folder and enter battle folder. You will find several folders containing historical battles files. And same like before find descr_battle file and modify it the same fashion like campaign files.

Experimenting

There is a lot of things that you can do only by modifying existing files. The most interesting thing, is that you can create custom battles and modify campaign starting stats, like state ownership etc.