Age of Wonders 3 already had a pretty good level editor in the game for players to use to make their games a little bit more customised to their liking. Now the developers have announced that they're going to add mod tools to the game in the future
Triumph announced the plans in a recent blog post. The tools will be implemented within the next patch for the game and will be compatible with Steam Workshop as well as various other mod making avenues. You'll be able to effect certain parts of the game like the game balance and you can add new specialisations and units; however you won't be allowed to tweak the core gameplay, models or textures with the tools provided.
Mods will have a switch in the launcher to turn them on and off, and will be useable across the single-player and multiplayer parts of the game; so no mods that give you an unfair advantage. More rules and features will be made clear in a future announcement.
