Training Dungeon

[Faielyn]

So for the starting portion to my campaign I am having the PCs join an adventuring guild to give some reason for these random people to stick together. This is starting at level 1 and has at least 1 new player who has not tried D&D before (An elven spellcaster) and I wanted the adventurer guild to have this underground training dungeon where they send parties to bring them up to snuff and also so I can test my PCs on their comp, weaknesses, strengths, and general ability to function. The major problem I am having is monsters, I need a believable way to have a repopulating dungeon that both tests their strengths but doesn’t murder them. I tossed around the idea of having bandits and criminals be the opponents but I don’t want to limit the party to non-lethal damage in this. I also thought of a bunch of wizards and druids using Summon Monster/Summon Undead/Summon Nature’s Ally to populate the dungeon but that limits me severely unless someone can point out an extended table for these spells as I would like more flavour for my creatures than woodland animals and a flaming beetle. If nothing else I will go with the second option since it seems the like the best way but I wanted to poll the community to see if I am missing a good idea. Also for the record the party comp is a swordsage, elven caster, unknown melee brute, and complete unknown (not much help I know but I have yet to do a discussion with the whole party on how everything will go so there is that.)

[Cybershark]

You're the DM.

Maybe have a few summoners or alchemists around. Have them specialize in making humanoid constructs/outsiders that mimic the behavior, bodily functions, and appearance of certain specific races (orcs, humans, elves, dwarves, dogs, cats, wolves, etc.)

These constructs/summoned monsters should basically have identical stats to NPCs and creatures that they simulate, but should obviously be unrealistic in appearance. Say that the adventuring guild has spent a lot of time perfecting this after they ran into trouble using lowlifes and thugs to train their adventurers. This can even lead into a plot point later on in the adventure when one of the folks that MAKES these constructs for the guild is kidnapped by a BBEG and forced to make clockwork soldiers for him, for example.

[Extra Anchovies]

A Warlock of 6th level or higher can learn the invocation The Dead Walk, which allows them to cast Animate Dead as a spell-like ability at will. They do not need to supply the material component for it, but if they don't, the undead crumble to ash after one minute. That's more than enough time for most combats, so perhaps the guild could have a mid-level warlock on staff as the testing supervisor? If the culture doesn't have a strong burial tradition they could have a ready supply of corpses, and by not using any intelligent or pain-feeling creatures there aren't any moral concerns.

[Cwymbran-San]

In the Forgotten Realms setting, there is a monster that devours other monsters and gains the ability to produce copies of said monster to populate the area and hunt for it's "master". I am AFB right now and at a loss for the name, but i know it exists.
Could be a plausible explanation and makes for a fine bossfight now or later :-)

[Stewzors]

Tbh I'd just fluff it as they were all "illusions" and they all attack as per normal statted NPC's just doing non-lethal damage.

It's a low level training dungeon after all, I wouldn't spend too much time statting it properly as they wont need it for very long.

[Theobod]

I think Effigies probably does what you are looking for.
Explain to the players via their instructor or invigilator that the following is for training purposes but the danger is very real, though there are safeguards in place, explain that medical supplies are on hand in each room and that the foes they face are expensive and hard to replace but easy to repair.

Thus: The party will be introduced to 'The Slain Sign', at any point them, or their foe, may step back and raise both/two arms/limbs above its head/sensory centre and cross them over, doing so renders the Adventurer/Enemy 'slain' for the purposes of the fight, the monsters will use this if dropped to single digit HP and the players are encouraged to do so if they feel genuinely threatened or get seriously injured. Striking a 'slain' foe is an automatic fail for the whole group (and the Effigies are programmed not to) and if any member calls 'Emergency!' at any point the exercise stops and a white box containing potions (that is otherwise to be ignored) opens for administering aid in the case of a legitimate medical emergency.

Explain to them that being 'Slain' is not a fail and infact any healing magic delivered to a 'Slain' party member allows them to (at their own choice) lower their arms/tentacles/pseudopodia/whatever. Having to call 'Emergency!' however scuttles the attempt and voids the score (but allows retaking of the exam without penalty and is there for 'legal reasons').

This instills a sense of formality and legitimacy to the proceedings, makes the party feel like they are being properly examined and tested in a safe but adequate setting and is relatively inexpensive (due to Repair spells) to reset for the next group if the Guild has a few low level casters on staff.

[Inevitability]

I think Effigies probably does what you are looking for.

They're a bit pricy, though, and a lucky hit may just destroy them completely.

I recommend using Astral Construct. The construct's appearance is mutable enough (and with a high enough craft (sculpting) check indistinguishable from the original) and they're completely expendable.

[Calthropstu]

So for the starting portion to my campaign I am having the PCs join an adventuring guild to give some reason for these random people to stick together. This is starting at level 1 and has at least 1 new player who has not tried D&D before (An elven spellcaster) and I wanted the adventurer guild to have this underground training dungeon where they send parties to bring them up to snuff and also so I can test my PCs on their comp, weaknesses, strengths, and general ability to function. The major problem I am having is monsters, I need a believable way to have a repopulating dungeon that both tests their strengths but doesn’t murder them. I tossed around the idea of having bandits and criminals be the opponents but I don’t want to limit the party to non-lethal damage in this. I also thought of a bunch of wizards and druids using Summon Monster/Summon Undead/Summon Nature’s Ally to populate the dungeon but that limits me severely unless someone can point out an extended table for these spells as I would like more flavour for my creatures than woodland animals and a flaming beetle. If nothing else I will go with the second option since it seems the like the best way but I wanted to poll the community to see if I am missing a good idea. Also for the record the party comp is a swordsage, elven caster, unknown melee brute, and complete unknown (not much help I know but I have yet to do a discussion with the whole party on how everything will go so there is that.)

Illusionist.

[Shackel]

As the DM, you have a lot of free reign with making this work beyond what is listed in official books. One idea could be that this dungeon was not built, but 'discovered': maybe some magical anomaly has left the echoes of memories of the original low level dungeon around, leaving it able to be repeated time and time again, for the memories just reform after a certain amount of time.

Add in Theobod's ideas of being able to drop potions on you whenever an emergency is called, and there you go! If death is the issue, perhaps they have a ring that immediately hits them with a Cure Serious Wounds or something if they're about to die(not just drop below 0) which sets off something that temporarily banishes or scatters the memories of the dungeon.

[Inevitability]

In the Forgotten Realms setting, there is a monster that devours other monsters and gains the ability to produce copies of said monster to populate the area and hunt for it's "master". I am AFB right now and at a loss for the name, but i know it exists.
Could be a plausible explanation and makes for a fine bossfight now or later :-)

What monster, exactly? I'm kind of interested.

[Extra Anchovies]

What monster, exactly? I'm kind of interested.

A quick look through Monsters of Faerun turns up the Deepspawn (p. 32), a CR 8 aberration. A deepspawn's "children" are completely loyal to it, and it's got some SLAs that make it troublesome to contain (constant Detect Thoughts, 1/day self-only Heal, and Hold Monster once per three rounds), so it may not be the best fit for OP's goals.

[Cwymbran-San]

A quick look through Monsters of Faerun turns up the Deepspawn (p. 32), a CR 8 aberration. A deepspawn's "children" are completely loyal to it, and it's got some SLAs that make it troublesome to contain (constant Detect Thoughts, 1/day self-only Heal, and Hold Monster once per three rounds), so it may not be the best fit for OP's goals.

That was the beast i was thinking about.

True, it's offspring have a certain loyalty towards their "creator" but that is something you could fluff away.

Just the general idea of an abberation, chained/force-caged within the confines of the guilds dungeon, being fed assorted monsters to replicate...after the characters fight their way through training they might be wondering where all the surplus baddies are coming from.
Until they find out that the benevolent guildmaster has adventurers capturing monsters to give to the Deepspawn...

[Metahuman1]

Tbh I'd just fluff it as they were all "illusions" and they all attack as per normal statted NPC's just doing non-lethal damage.

It's a low level training dungeon after all, I wouldn't spend too much time statting it properly as they wont need it for very long.

I'll second that the Illusions idea is a good one. A few Illusionists, maybe an Artificer on staff at head quarters, a couple of bards/factotums/rogues and a Cleric and Druid, and a few warrior types form different classes staff to supervise the creating of Illusions so the wizards are doing realistic representations of the fighting styles said adventurers will be up against.

Boom, makes sense, would be reasonably affordable for the organization, works with out moral concerns or dead PC's, preserve's suspension of disbelief, takes five minutes or less to explain and get on with the game.

[ekarney]

Well my first thought upon seeing the title was "Goblin Slavers"

Upon reading the OP that doesn't seem appropriate
But Goblin slavers.

Now now, hear me out.

The guild has an agreement with the slavers - they send some newcomers into some tunnels, being slavers the goblins use non-lethal weapons, however they still do have spellcasters and the like however they'd still use non-lethal variants for example they'd use a watered down of alchemist's fire that instead of burning, just stings a lot (same damage, just subdual). The guild (and Goblins) prefer that the PC's use non-lethal means to dispose of the Goblins and are happy to lend them training weapons, however the Goblins are pretty well off at this point, and being Goblins the occasional death doesn't bother them too much, in addition, consider adding a stipend as a reward for not getting knocked out, say 50gp each which if the PC's fall will instead be used to ransom the PC's back from the Goblins.

Now if a PC is knocked out you can give them say 3 rounds before a Goblin patrol finds him/her and another 2 before they start carrying the player off, where you can give your players a choice - fight more goblins and either use resources, or carry the PC with them for more gold or leave them, and let the guild pay their ransom.

There should also be incentives for getting through the dungeon without killing any Goblins for example and extra 25gp or so (they are level 1 right?) or maybe getting to do "Adventurer Guild Approved" quests for the slavers like "Capture this criminal we want as a slave" or "one of our raiding parties got captured by Kobolds, bring them back alive" that they can be rewarded with cool non-lethal goodies.

Now I know you said in the OP that you didn't just want it to be non-lethal, but this way it's definitely safe and you can explain to the players what went wrong without them losing their characters, and it's fairly low cost because otherwise you either have to reroll or it becomes expensive paying for true resurrections.

[Thurbane]

You could (partially) populate the dungeon with self-spawn undead like Wights, and feed in a supply of criminals on death row.

You could also have enslaved/trapped outsiders who use their Summon abilities on a daily basis.

A high level Binder binding Zceryll gets pretty much unlimited monster summons. Maybe he can team up with the Warlock mentioned above.