The Basic ChassisClerics have decent attributes across the board, with 12 for all physical abilities and 14 for all mental abilities. They're a primarily mental/social focused class, but they don't come off as big brains like Wizards or eagle-eyed masters of perception like Scouts (though they are, attribute-wise). Their physical abilities are adequate, but most Clerics are too weak to pile on heavy armor, too clumsy to be reliably sneaky, and not nearly resistant enough to poison and other environmental hazards.
Cleric's primary skill set involves non-magical healing, Exorcism, and melee combat. As melee combatants, they're solid but not impressive: average skill 14 isn't enough to reliably get hits against dangerous opponents nor to defend against them, and ST 12 doesn't do very much damage. It can be humbling to see the rapid-striking Swashbuckler or Weapon Mastered Knight still have a better effective skill than the Cleric while doing much, much more damage. That said, Exorcism is a life saving skill in the face of curses, possessions, and other threats of the delving experience, and Clerics have the Willpower and related advantages to be successful exorcists.
Their secondary skills are mostly focused on religion and healing, making Clerics useful for identifying demons and undead on the one hand, and scoring a little extra cash by recovering bits from dead monsters. Stealth and Climbing are background skills for them, and combined with a low DX and generally medium-heavy armor means that Clerics should leave the scouting to someone else. They have some abilities as public speakers, but don't generally have the advantages and skills to be an effective public face for the delving band.
Advantages and DisadvantagesUnsurprisingly, every Cleric has Clerical Investment, and they also have 30 points in Power Investiture, which is a leveled talent that lets them learn spells from limited lists without prerequisites. Between IQ 14 and Power Investiture 3, every starting cleric is a decent spell caster.
Clerics also get 25 points in "Holy" advantages: things like supernatural Allies, Faith Healing, and Truth Faith (Turning). True Faith is the big winner here, since Will + Power Investiture + equipment bonuses starts at 17 and can easily go over 20 for a starting Cleric, and the ability to force every undead monster to stay at least 5 yards away from the Cleric is enormously helpful against a monster type that is generally focused on melee hordes. Not every Cleric takes Truth Faith, but it's a common and solid choice. Faith Healing is another good option, but most Clerics can use magic for healing and don't need Faith Healing on top of that.
There's another 20 points worth of optional advantages that can also be used for more Holy abilities, to pick up more Power Investiture, or for more mundane abilities like extra ST or DX. None of the suggested optional advantages are really noticeable, and more Power Investiture or more Holy abilities are usually the way to go.
Clerics have to pick a 10 point disadvantage such as Honesty or Vow (No Edged Weapons) that represents their Pact with their deity. As long as they adhere to the disadvantage, they can use their Holy powers, even in areas with no sanctity. That rule has been confusing to every group I've every played in, since Cleric spells are affected by Sanctity, but as written, Powers are only affected by the Pact disadvantage. Which is actually very helpful for Clerics, since they can do things such as heal with Faith Healing or turn undead with True Faith, even in the middle of the high unholy temples of the Black God of Undeath. It's an important rule, and easy to get wrong.
The rest of the Cleric disadvantage list is focused on "good" disadvantages, such as Compulsive Generosity or Vow (Vegetarianism). Nothing particularly stands out, but it does push the Cleric towards being something of a goody-two-shoes. It's possible to play a sleazy Cleric of the God of Thieves off the base list, but it can be some work. Fortunately, there are variant Cleric lenses for people who want that sort of thing.
Cleric Skills or Cleric!
Cleric! is one of the weaker wildcard skills. It mostly deals with the cleric's knowledge role, covering skills like Theology and Hidden Lore (Undead). One of its big advantages is that it covers Exorcism, and thus Destiny Points (for games using those rules) can be spent on those tricky and difficult contests. The other advantage is that most of a Cleric's knowledge skills are already at the same level as the Cleric would get with Cleric!, so there's not the same sort of breadth or depth question that Knights and Swashbucklers have to worry about.
Arguably, spells are the real reason to play a Cleric. Of the original archetypes, only Clerics get the versatile and inexpensive Major Healing, and starting Clerics can buy it with their initial level of Power Investiture. The rest of the spells are a grab bag of general buffing and utility, but Command, Continual Light, Cure Disease, Purify Air, Recover Energy, Resist Fire, and Watchdog are all solid choices for some of a Cleric's twenty starting spells. Higher levels of Power Investiture are worth more for the skill bonus to all Cleric spells than for the extra spells available, though Dispel Magic, Divination, Gift of Tongues/Letters, Instant Restoration, and Regeneration are all useful. The last two, especially, can turn a disastrous fight into a merely expensive one, if the Cleric has a Power Item large enough to cast either of these fairly expensive spells.
The biggest problem with the Cleric spells is not what is on it, but what isn't. While Clerics don't suffer for the crippling overspecialization problem of the various summoners, they're still well confined to the healing and support role, and much of their support is purely defensive with the various Resist (thing) spells. They don't have much in the way of offense or battlefield control, and they lack the general purpose "screw with the GM spells" that wizards get, such as Shape Earth, Apportation, History, Trace, Invisibility, or Flight.
Clerics and RaceThere's no race that's especially well suited for Clerics, though any race without an IQ penalty is playable. Dwarven Clerics are a good choice for more combat focused Clerics, since Pickaxe Penchant is a cost effective way to become a better melee combat while being able to hurl axes at range. Dark One Clerics seem like a good idea from a superficially munchkin, but it's spending 20 points for a minor bonus to secondary skills and better power items. These are good things to have, but probably not worth the cost, and the other advantages such as High Manual Dexterity will rarely come up. On the high end, Celestial is conceptually appealing but practically no better than spending 75 points on the equivalent set of attributes and advantages, and while Infernal provides a better set of racial disadvantages, the absolute requirement to buy off the Weakness to areas with High Holy Sanctity means that's its really more of a 95 point template, only available in the most high powered games.
Clerics are a unique template, in that they're the only template to have an entire book devoted to its variations. DF 7: Clerics provides the first formal reference to the Good-Evil, Bunny-Squid morality axis implied in the DF works, and also provided 15 variant Clerics for Gods of the City, Death, Fire, Storms, and so on. The variants get slightly different skill lists, advantages, and disadvantages options, and they also get massively different spell lists.
I'm not generally a fan of the variant Clerics, since they tend to move spells that I consider essential or at least very important to Power Investiture levels I generally don't want to buy, in exchange for making a spell I would have been able to buy normally available slightly earlier. Still, they do give a Cleric of the appropriate deity type a lot of flavor, and in the right campaign, they can be especially powerful: a Cleric of a God of Storms on a sea-going campaign, for instance. Each one needs to be judged on their individual merits for the campaign and the tastes of their player; on the whole, I'd rate them all as slightly weaker than the basic Cleric but situationally more powerful.
Equipping ClericsClerics tend to equip much like Knights, but with less strength, so their armor tends to be somewhat inferior to conserve weight. The basic choice of axe, mace, sword, or flail remains, with the normal trade-offs: cheap swords are versatile but fragile, basic axes are inexpensive but dull, fully kitted out axes are much cheaper and nearly as good as expensive swords. I generally favor the Dwarven, Balanced, Fine axe for around $1500, especially for Dwarven clerics. Expensive weapons also double nicely as power items, so if there are points available to trade Points for Money, there's no reason to not make the axe Silver-coated, Spiked, Hammer-headed, Holy, and Ornate. For about $2500, it's already a 13 point Power Item, helpful for getting off those important spells such as Great Healing or Restoration.
Blessed or High Holy Symbols are other good choices for gear (a High Holy Symbol makes a good Power Item, too). On the less exciting side, potion belts stocked with healing potions or cheap Holy Water (see DF2 p 3) are another item competing for scarce dollars. A lot of Clerics buy surgery kits, since they would like to cut up monsters for loot, but at $300 and 15 lbs, it's not an investment that I've seen pay off very often unless there's a Barbarian or Half-Ogre in the delving band to tote the thing.
Clerics are often constrained by weight more than dollar amount: the need for decent armor, a weapon or two, a shield, potions, and healing kits can easily put the Cleric into the dread medium or heavy encumbrance. Whenever possible, Clerics should try to distribute the load by passing equipment to stronger members of the band. Clerics don't act as scouts, and instead are in the center of the band like a wizard, so not having their stuff immediately on hand is less of a disadvantage.
Clerics in PlayProviding healing is a vital role, so Clerics are a necessary part of most delving bands. They also have a lot of utility in identifying and removing curses and unholy stuff, as well as figuring out which dark temple the band has wandered into this time. A cleric's player usually has something to do, even if it isn't always superbly interesting, when out of combat.
In combat, Clerics have to accept that they're second tier combatants at best. They don't have the ranged abilities of a Scout or archery focused Mystic Knight, nor the straightforward melee mayhem of a Knight or Swashbuckler. Even the Barbarian hits harder and straighter than the Cleric, though the Cleric is marginally better than the Bard, Druid, or Thief. Generally, the Cleric wants to fight as part of the battleline, but not the focus of it. On the side where they can be protected by the Knight or Swashbuckler while still helping keep the Scout and Wizard out of trouble is a good spot. In larger delving bands, a Cleric with a pole arm is happy to be in the second rank, with the ability to cast buffing or healing spells on the front line, attack past them, or Concentrate on Truth Faith, as appropriate.
In SummaryClerics are a good, but not great, archetype, and one best suited to the kind of player who likes being in the support role more than being in the spotlight. It's not an easy class by any means, since playing one does require understanding the GURPS Magic system and juggling trade-offs. Even something as apparently simple as True Faith (Turning) can become complicated, since the power lasts a few seconds after the Cleric stops concentrating and that means undead can be repelled even as the Cleric attempts a quick healing.
It would be nice to buff the Cleric by adding more combat abilities or more spells, but each option either pushes them into the Knight's or Wizard's niche. Without Trained by a Master or Weapon Master, the Cleric is never going to be a first tier melee combatant, and without a better spell selection like the Wizard's, they're never going to be a general utility caster.