How to play
The Sanctum Romanum Imperium campaign (or "campaign") uses the "Epicrpg" system by Dark matter studios, if you are in my game, don't worry, I have the book. If you aren't, it looks good so far and has received good reviews. Lets face it though, if you are here, you are either one of my players or probably know all about Epic rpg already.
Unfortunately the Dark Matter team have a tendency to use "unique" terms for common rpg concepts, so a translation is on my ongoing "to do" list. You need two ten sided dice and remember this is one of those "gritty" or "realistic" games I like to run now and then.
We will use the point buy attribute system from the book. It's particularly important that you have a proper look at the way "talent" works in this game (see the "translation"), significant savings in experience point costs for skills can be had just by ensuring that a. the relevant mental attribute (it's always a mental attribute) has a good bonus and b. you aren't buying high levels in skills governed by too wide a range of mental attributes.
Roll up a regional background. Characters will be beginning with a few years extra experience under their belts, so opportunity exists to gain entry to some guilds originally precluded by the character's birth, though no one can rise from peasant to Emperor. The guild list is always, always a WIP. I estimate it is taking me about an hour (with a good internet connection) to do the background work for a guild, skills are easy. If you want to play a specific type of character, tell me, I will make a guild for you. Three of the guilds already are there due to player requests.
While slavery is not practiced in the Holy Roman Empire, serfdom was close to it and tenant farmers were still legally bound to their masters land, even if demand for labour often made this unenforceable. Treat all "slave" rolls on the background table as being various types of serfdom or other forms of indentured servitude or forced labour.
It wouldn't be one of my games without a few changes. Obviously I'm not happy with the prices on the equipment list for this setting there is a new one to cover arms and armour, representing what you might pay in the middling sized "city" of Regensburg. I have added new skill and stat minimums for bows and other missile weapons. Everyone knows all about longbowmen and the key benefit of gunpowder weapons was that any idiot could be shown how to use them, so I am sure you can see the logic. There is also a new ranged arms speciality to go with it.
Characters may begin play using any of the Epicrpg magic systems: Alchemy (of course!!!), Metaphysics, Philtrology (herbalism and the mixing of potions), Theurgy (Pagan magic and Witchcraft) and Shen (The magic of Pagan Warriors). Additionally, there is a system allowing characters to pray to saints in order to gain effects similar to those created by a spell. This is the default magic of the setting and is the only miraculous thing that is likely to not arouse the ire of the superstitious people of the 15th Century. Even then you should keep the example of St Joan of Arc foremost in your mind.