When I published my system-agnostic setting, the Spire in 2018, I planned on adding supplementary information to this site. It’s taken a while to get around to that, but I needed some distance between it before I made a start; and since the book has now been downloaded by lots more people than previously, it seems a good time to start.
For the most part, standard classes and monsters, spells and magic items work perfectly well with the setting. It was, after all, designed to be broad. I was tempted to just leave it as it is, let other people create what they like, but a few people have asked for more, so let’s see what I can do.
Appendix 1: Clerics
First off, let’s talk about divine magic. In this setting, the Spire is the source of divine magic for the three religions mentioned in the book: the Aspirants, the Consumers, and the Brave & Bold. These gain their divine powers from the very presence of the edifice, and the higher they climb, the more accessible those powers are.
In game terms, each level corresponds to a spell level. 1st Level spells can be accessed from Level 1 upwards; 2nd Level spells from Level 2 upwards, and so forth. At ground level outside of the Spire 1st Level spells only work a mile away, no more. Other powers, such as turning undead (for example) function in any level of the Spire, including in the Roots. These abilities still function a league from the structure (3 miles), but not beyond.
Of the three, only the Aspirants are typical clerics or priests (depending on your system). The other two differ slightly, replacing the normal turn undead ability with the following:
Order of the Consumers
The priests of the Church of Consumption gain additional powers by eating another creature, animal or otherwise. They gain one of the creature’s special abilities, for 10 minutes (1 turn) per Character Level/HD.
For example: if a Consumer eats the flesh of a giant spider, they may gain the ability to climb walls or spin webs, or become venomous. If they ate the brains of a sorcerer, they might be able to cast arcane spells for a time.
The Brave & the Bold
Similar to the Consumers, these priests gain abilities based on the Hero they have chosen to worship. A priest of this religion must chose an adventure to worship and follow: if the Hero is a cleric (say, an Aspirant) they would gain the ability to turn undead. If they followed a Heroic Fighter, they would gain the attack or damage bonus of a Fighter; a sorcerer Hero would grant them the ability to cast arcane spells. These abilities are always less powerful, and are either half (round down) the Level/HD of the Hero or the Cleric’s Level, whichever is smaller.