This is one of the overlooked gems of GURPS, in my opinion: GURPS Banestorm: Abydos, by David Pulver.
In the interest of full disclosure, I am friends online with David Pulver, and I playtested this book twice (once when it was abortively slated for a 3rd edition release, and then again for 4th edition.) So I'm not unbiased, but too bad - I'm biased in favor of reviewing stuff I like, and this is one of the supplements I like!
GURPS Banestorm: Abydos
Hidden City, Forbidden Lore
by David Pulver
Steve Jackson Games, December 2008
Abydos is situated on an island in the middle of a lake bounded by three states in the Yrth setting of GURPS Banestorm. The conceit of that setting is that the world is magical, and dark elves accidentally triggered a magical backlash while trying to summon up an apocalypse against their enemies, the orcs. Instead, they caused a series of "banestorms" that pluck hapless folks from other worlds and dump them on Yrth. These include a wide selection of people from Earth, who brought their own cultures and religions with them. They've changed, but still reflect much of the original conflicts and beliefs of their Earth versions.
Abydos is a city of necromancers - but Christian necromancers. A heretical monk supposedly discovered the lost books of Lazarus of Bethany, the Lazarus who Jesus raised from the dead. Those books extol the raising of Lazarus, expose Peter and Paul as revisionists, and exonerate Judas (St. Judas, to the Lazarite Christians.) Basically, they see raising the bodies of the dead to serve and aid the living as totally normal, natural, and right. Needless to say, the more mainline church in the world disagrees and periodically tries to expunge them, without much success so far. Simultaneously, they've done their best to seal off the island city by wiping it off the maps (hence, why it isn't on the normal maps from GURPS Banestorm) and by denying its existence when not actually whipping up crusades against it.
So Abydos is a medieval-cum-Renaissance city, similar to those of Italy, but with a magical bent, a lot of undead, and a strong Christian tradition (albeit a heresy).
Lots of the elements are really well done - an order of vampire monks explains their inability to tolerate holy symbols as suffering on the cross as Jesus had, and their fatal flaw against stakes as being vulnerable to a spear like that which pierced Jesus's side.
Plus it's not just black-robed necromancers trailed by zombies rubbing shoulders with demons and whatnot - demons are evil, and demon-summoners are actively hunted down as sinners! The black-robed types are monks or priests or scholars.
All of the hersey makes sense, especially if the implication by the more mainline Christians in the setting that the original lord of the city (Lady Ravenjoy) warped the teachings just enough to justify her necromantic studies and
- the Ravens. A female force of nobles, many mages, who act as cops and rulers (with limitations - there is a council, etc. that provides lots of chances for politicking.) Their current ruler is Gabrielle Boneshanks, who died and had herself raised as a zombie and then Soul Jarred the body.
One example Raven is a little unlucky (for her partners on the force) and an ideal friendly NPC or as a PC.
- the Legion of Polished Bone. A skeleton army (and police force) made up of the defeated legions of Megalos's crusades.
- the Naglfari. A mafia of Northmen, named after the ship of fingernails of the dead Loki would sail at Ragnarok. Don't mess with the Jarl of Jarls.
- Anti-Lazarite Christian Terrorists. They fundraise with crime, which causes friction with the northmen.
- the Flesh Library. Living slaves held in stasis and tattooed with the words to a single spell.
- a (magical) school with fraternities of students and a history of annual bad behavior, duelling, and intra-student rivalries.
. . . and a lot of hooks.
On to the crunchy stuff.
- a couple new spells (one of which I think I suggested way, way, back in the day - a mass Death Vision effect, basically*)
- stats for everyone you'd possible fight or want to run.
- a nice map of the city, suitable for GM and player use alike.
- enough details, costs, etc. to play in the city without foundering over big questions (how many people? Where does the food come from?) and little ones (How much is the pheasant special at that restaurant?)
Playing in Abydos
It's very well set up for a Abydos-based setting, especially for either a cop-based game (as Ravens) or a private investigator game. Garrett, P.I. could easily have an analog here, delving into troubles of vampire monks, wizard-nobles, magical student fraternities, spying foreigners, and racial, ethnic, and religious struggles.**
The city is tight but deep, and the writing gives enough details and enough hooks to be immediately useful and easy to expand on, as well. Every NPC has a secret, a desire, or a complication, as does every shop or location. Some are benign, others pretty nasty, and all mean you get a feeling of a living place with interconnected people. It's small enough to let players get familiar with it quickly but deep enough to provide many, many sessions of play. It would do well as a sandbox (lots of crime to work on, or commit) or an episodic drama (a dame walks into your office, with a problem with her zombie husband and his necromancer lover). It's set up well enough to be played light or bleak.
How is it for DF or for non-GURPS games?
If you've got a strongly Christian-influenced church system in your game world, you won't have to change much. But it would take a lot of work to ram this into a Good/Evil alignment system. It might work with a Law/Neutral/Chaos split, though. These are slave-owning, necromancy-approving heretics who are policed by zombies, led by necromancers, and prayed for by vampires. Yet they're believing Christians, society is generally law-abiding, and individuals range the gamut from genuinely nice people (but ones who'd raise their dead siblings as zombies to keep them working in the family shop) to evil bastards fighting on behalf of freeing slaves and throwing down the necromantic order.
Another caveat is that Abydoes uses the standard GURPS Magic system, without any of the clerics vs. mages split of Dungeon Fantasy (or, for that matter. D&D clones). In that setup, all spells - healing, necromancy, fire, earth, illusion, etc. are mage spells. Priests get so special abilities unless they are also mages. It's a big change, and adapting the setting to a clerics & priests vs. wizards approach would take a bit of work. I've done it the other direction (playing D&D settings in a game without clerics getting spells) so I know it's a little work.
A free and easy Turn Undead ability would make the legions of undead used by the city much less scary, and so you'd either need to nerf the ability or buff the undead against turning. For example, "Skeletons cannot be turned while their Raven commanders are alive," say, or "Undead are turned at 2 levels higher," or just make it impossible. After all, they are fellow Christians, and believe just as strongly as you do in the same god . . .
I highly recommend this book. It's atmospheric and cool, and it makes for an interesting place to visit or base out of without being a "standard" fantasy city or a typical "evil" city.
* David Pulver said that he remembers me suggesting it, too. I probably didn't come up with the cool name though.
** David Pulver has confirmed this is how he used Abydos in his own gaming.