To access and play the Medieval Kingdoms 1212 AD campaign, follow these steps:
If you are looking for a written strategy guide (a "paper" on how to win the campaign), the community produces "AARs" (After Action Reports) which serve as case studies. total war attila mod medieval kingdoms 1212 ad campaign link
Because of Steam's file size limitations, the mod is split into roughly a dozen individual workshop items (including the Scripts, Campaign Base, Custom Cities, and up to 9 distinct Models Packs). Subscribing to them all is mandatory. To access and play the Medieval Kingdoms 1212
The mod has been in development for years, and its (officially released in stages) is now fully playable, stable, and one of the most ambitious mods in Total War history. total war attila mod medieval kingdoms 1212 ad campaign link