My players and I started a brief discussion on Sunday about the utility of non-fighter types in my game, which I think reflects on deliberate choices in GURPS Dungeon Fantasy. Here are some of my thoughts about combat and non-combat specialists in DF.
The thing about DF is, everyone is an expert-level specialist.
Non-front line fighters will never be able to keep up with front-line fighters in combat. Combat that is significantly dangerous to Barbarians, Knights, Martial Artists, and Swashbucklers will overwhelm non-front line fighters. Even some of them - the Barbarian and the Martial Artist - give up some direct combat ability for flexibility in other areas, and are more at risk than the other two. Holy Warriors fill a specific niche - they'll pass as front-line fighters, but aren’t up to the Knight or Swashbuckler level; they excel against "evil" creatures.
Conversely, front line fighters will never be able to keep up in non-fighting tasks covered by other experts. Traps and locks will utterly frustrate any front-line fighter. They are useless for much besides setting off delicate traps. They can't cast spells or disarm traps or open doors without force. Only Clerics can heal. Only Wizards are any good at spells. Only Bards can use songs to sway or calm or incite. Only Artificers can build gadgets on the fly.
The split in DF is that if you take a non-front line fighter, you're as much as admitting you can't hack it against the toughest foes. But if you take a front-line fighter, you can't hack it on technical tasks. Knights, specifically, are so myopically focused on combat they can't do much else besides force doors and kill monsters. If they dump most of their points in more combat abilities and not much in strength, they can't even open doors well.
In this way, it's a lot like a higher-level D&D or Rolemaster game would be. Any trap dangerous enough to require disarming instead of absorbing or bypassing needs a Thief, because no one else can hack it. Any evil shrine bad enough to do evil things needs a Cleric to cleanse it. Any wound bad enough to slow you down requires a Cleric to heal it. Any magical defenses or barriers worth noting requires a Wizard to bypass. Anything on guard enough to require sneaking to surprise needs a Thief or Scout. Wizards will be useful in and out of combat, with the right spells, but they can't out-kill the fighters in combat. You can try some overlap (either with a 50-point lens, or just pouring points into a non-template skill) but you'll forever lag the experts. That's part of the game design. It's niche protection in the best way (for more on niche protection, see here and here)
My game is combat-heavy. But it's also obstacle heavy (fortified entrances, heavy doors, magical barriers, etc. and that's just so far on level 1). Part of the "non-combatants are useless" meme I can see starting to grow in my own game is because, as luck would have it, the group really hasn't hit many of the evil traps, horrid puzzles, killed-by-special-methods monsters, magical barriers, unholy sites, skill/knowledge challenges, and tricky negotiating opportunities that await them elsewhere. There have been some already, but they've either been bypassed, bludgeoned down and walled off (such as the gargoyles), or assaulted with Shape Earth (such as the black door and the trapped hallway from last session). Some of this is play style - if you think it's always fine to bash the chest to pieces or kick the door down or cure damage after setting off the trap, maybe a Thief isn't going to have much to do. If you never scout, yeah, Scouts are useless. If you smash a hole in the floor instead of doing research to find the password for the magic staircase, the Sage or Wizard will be less useful. If you deal with evil shrines by taking the valuables and leaving them dangerously evil, the Cleric is less useful.
I personally think that in RPGs, you get the game you play. If you make non-stealthy fighters and frontal assault everything in a loose combat order, you’re going to get a campaign heavy in chaotic, turns-on-a-die-roll fights with lots of ambushes by stealthy opponents. If you make a wizard-heavy party, you're going to have a "15 minute adventuring day" type of game where the whole group adventures based on available energy, and where magic resistant foes are a special challenge and No Mana Zones seem unfair barriers. If you favor diplomatic types and talking, you'll negotiate more overall in the campaign.
The GM influences just as much as the players - it's probably 50/50 GM/combination of the players. If both react to the perception of "campaign needs" you can get a feedback circle - we fight a lot, so we need more fighters in the group, so we can't navigate traps or negotiate, so we take more damage and have more fights and need more fighters. The GM then tosses more and tougher fights at you because you're too hard to challenge in a fight and too hapless against other threats.
The way out of the loop is to just get out of the loop - both the GM and the players need to do it.
How? The GM needs to set challenges and let them sort it out themselves, and not modify them to match a lopsided approach. Example: "Okay, you wiped out Orcus and his buddies in three rounds with no sweat, but now what? The temple exit is trapped, the treasure is behind a forcefield, and Orcus will re-form in 1 minute if you don't destroy his unholy altar with clerical rituals."
The players need to leverage the skills of their non-front line fighter buddies, and the non-combat skills of the fighters so they aren't "sit around until we fight" types. They need to avoid trying to outrace the GM like he was a video game AI ("I've maxed out my combat skills and win all fights in the game easily, finally. Okay, next quest . . . ") You can't win an arms race with someone with unlimited resources, so concentrate on achieving your goals in a fun manner without trying to maximize your ability to beat one challenge. Pick a guy that's fun and useful, and find ways to get more out of your abilities.
I think there is always room for the expert, the non-combatant, and the utility character. You can't pull your weight when the combat specialists are needed, but the game isn't only combat, unless you make it out to be. If all you bring are hammers . . .