Not the most important aspect of modding, but it's a nice little thing to know even if you don't end up creating a mod. This is a short tutorial on how to make the grand campaign and the Kingdoms campaigns longer or shorter. I always hated how one turn equals two years in Medieval 2. I understand that things took a lot longer back then than nowadays, or even in the early 19th Century, but I don't think it took twenty five years to go from Normandy to Sicily back then. So I decided to find some way to chop off at least half of how much time one turn covers, and this is what I found.
Go to descr_strat in the the imperial campaign. To reach the imperial campaign:
For Steam: Go to Steam (which will likely be in program files unless you moved the folder elsewhere): steamapps, common, Medieval 2 Total War, data, world, maps, campaign, imperial_campaign, then descr_strat
Once in the descr_strat notepad document, scroll down to:
Start _date 1080 summer
End_date 1530 winter
timescale 2.0
Simply change the number for the timescale to anything below 2.0. I like to make it .50 since it greatly slows down the campaign time, but not to a point where a year takes forever.
For non-steam users, go to either program files, sega, medieval 2 total war, or wherever else the Medieval 2 folder is and do the same.
For Kingdoms campaigns, do the same, except when in the Medieval 2 folder, go to mods, and then pick which one of the campaigns you want to edit.
This also works if you want to make the campaign shorter, just set the timescale to 2.1 or higher.