Is it reasonable to have an extremely overpowered GMPC accompany the party early on to let them with enemies that they can't overcome on their own?

Question

I created a scenario that features an antagonist who has armies of demons and creatures at their disposal.

I made a gmpc character to help my players because the game features a ton of difficult enemies due to the style of the scenario. The gmpc should help the party deal with things like high-level demons and other stuff to protect mainly those enemies that are only prone to magic damage. The gmpc enables the party to focus on dealing damage against those threats they can safely engage.

In particular, the 5th-level PCs will be facing enemies that would kill them quickly without assistance, and they will face armies of enemies. This gmpc will be there to deal damage, tank hits, and crowd control; and generally take attention away from the party to deal with those situations that the party can't handle, while the party focuses on those enemies that they can overcome.

The stats are: Str 27, Dex 29, Con 20, Int 21, Wis 22, Cha 24, HP 16, AC 31.

Is it reasonable to have an extremely overpowered gmpc accompany the party early on to let them safely engage with enemies that they can't overcome on their own?

Answer 1

You are asking two different questions in the title and the body and they have different answers.

Is it reasonable to have an extremely overpowered gmpc accompany the party early on to let them safely engage with enemies that they can't overcome on their own? No, or at least not generally.

Generally, GMs should not also have a PC. This question has been addressed elsewhere and so I will primarily refer you to the answers to this question: Can the dungeon master have a player character?

However, to very briefly summarize, generally a GMPC will be more likely to annoy the players than improve the game and it will not give the GM the same type of fun as actually playing. Being a GM should be fun, but it is a very different kind of fun than being a player.

There are some occasional exceptions where it can work, but they are exactly that, exceptions. Also, they are best done in moderation. Fighting alongside a character of legend such as Drizzt Do'Urden once can be fun and creates stories that can be told, especially if the GM carefully makes sure that the Legend would not have won without the help of the PCs. Constantly fighting alongside a legend when you aren't a legend yourself makes you a sidekick. Most players do not want to be sidekicks.

If you really, really must have a GMPC, a support character that focuses on supporting the real PCs is likely to be less bad. This question has some answers that discuss how to mitigate some of the issues with a GMPC further, but even there the bottom-line answer is that you generally shouldn't do it: How should I restrain myself when both playing a character and DMing?

Is giving a demigod increased stats reasonable? Of course it can be, but not like that.

It is quite reasonable, even expected, that a demigod would have higher stats than a mortal. I would almost say it would be unreasonable for them not to have somewhat increased stats.

However, your suggested stats of "Str 27, Dex 29, Con 20, Int 21, Wis 22, Cha 24, HP 16, AC 31." Are...incredible. Those are far higher than I would expect a demigod to have -- other than the Hit Points, which are so low for a character like this I wonder if you made a typo (although you didn't mention level or class, so maybe it isn't too low). Still, you are the GM so if you say those are the stats, then those are the stats.

The real problem is that you want to introduce a GMPC with those stats. Other than possibly the occasional cameo, the players should not be outshined by an NPC. As I mentioned and as other questions detail more fully, a GMPC is rarely a good idea at all and, if you do have one, it should not be one that outshines the PCs.

Answer 2

Your GMPC is not as resilient as you think, which means you will have to use artificial tactics to not kill it.

I will put aside the question of “should you introduce a GMPC”, deferring to Timothy Wiseman’s answer.

Your GMPC is weak, believe it or not. Any spell or feature that deals half damage on a saving throw will make short work of it. At 16 HP, a single fireball can one-shot this character, even if the saving throw succeeds. You’re going to have to intentionally avoid monster features and tactics that can guarantee damage on successful saving throws. And even if you do this, you’re inviting your payers to accidentally kill him.

Wow, this guy is tough, he can survive a little friendly fireball if it helps take out the other enemies.

Narrator: He couldn’t.

That said, the solution is not to raise their HP, or make it immune to area of effect spells, or anything of that sort. The solution is to follow advice that says to rethink this plan entirely.

Answer 3

Your NPC should not accompany the party.

It's generally a bad idea in D&D to have a high-level GM-controlled character accompany the party and fight alongside them. It undermines the players' achievements.

I tried something like this in a campaign several years ago. I had a battle in which the PCs defended a city whose ruler was established as a high-level NPC. It made no sense for the NPC not to fight to defend their own city, so they took part in the battle. Unfortunately, it made the PCs feel unimportant.

I believe the PCs should feel like their actions are meaningful, even at low character level. Having them accompany a high-level NPC so they can fight high-level challenges is generally not a good situation. If the expected challenges are too great, the DM has the power to change those challenges to suit the party's level.

My recommendation is to use high-level NPC allies only as patrons, or to have them undertake their own missions away the party, so as not to steal their thunder.

Answer 4

Such a severe stat imbalance introduces complications that are likely to degrade the game for your players

Leaving aside the question of whether or not you should try to use a GMPC at all, such a significant stat imbalance between members of an adventuring party will make balancing encounters incredibly difficult. It's not that the PCs can't overcome the challenges you are envisioning "on their own", it's that they can't overcome those challenges at all.

For a character with such devastatingly high stats combat will generally be easy for them to win unless the opponents are really powerful as well. But the GMPC won't be the only one on the field, and your level 5 PCs will not be able to handle enemies that are are more than trivially easy for the GMPC to deal with.

For example, an enemy that has a chance of hitting a target with AC 31 will be extremely likely to hit any of the PCs with attacks. The outcome of such a matchup for your PCs is, therefore, very likely to be that they are spectators of the combat or all-but-helpless victims of the enemies.

This isn't really a GMPC problem so much as it is a level imbalance problem, similar to a player rolling a new character and joining the campaign at the same level as the other PCs. Regardless of other issues with GMPCs generally, combat encounters that require such high stats are not suitable for characters without those stats. Unless you've done some really tight design work (and I do not believe that D&D 5e allows enough precision in encounter design), you are designing a stretch of the game that your players can't really play.

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There is another issue around the GMPC's low HP. If enemies have a chance of dealing damage to the GMPC then the GMPC is going to be constantly at the edge of death. For an enemy with stats that make hitting the GMPC possible, one hit could be enough to kill! Especially considering the massive damage mechanic. And if the campaign is so difficult that the PCs need this GMPC, then it can't support that outcome. So you will end up with huge pressure to make the GMPC unkillable anyways, one way or another.

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A limited, narrative-focused section of the game might be workable with this setup

I still advise against it, at least at the level of needing to assign these stats to the character, but if you really want to use this GMPC to illustrate the intensity and difficulty of the scenario (like the might of the antagonists) you can use some scenes with them to do so. I have done this, and it worked well for me, but stats aren't really relevant because it's a narrative device used to flesh out the scenario. It is not a gameplay element with a plausible chance of failure due to chance. It's basically a three-beat sequence:

• Show how powerful the NPC is. Have them destroy an imposing enemy, or accomplish an amazing feat, in front of the PCs. Rumors of those things can work too, but "show don't tell" is valuable when using an NPC to demonstrate the campaign's challenge. This can be a combat or two, but I have found that a "cut scene" works better; there is no reason to leave any of this demonstration to the dice
• Show the NPC struggling to overcome the opposition. After the first step players will be aware of how awesome the NPC is, and seeing the NPC have trouble with challenges suggests that those challenges are incredibly daunting for the PCs
• Get the NPC out of the picture. Once the difficulty of what the players are facing has been demonstrated, it's time for the NPC to leave by any means you feel are appropriate. Being defeated by an antagonist even stronger than the NPC is a reliable method, if a bit of a cliché, but they can also retire, or take an important journey, or deal with something important while the PCs need to go somewhere else to deal with another important thing, or anything else

When the plot features a sequence that expresses "the NPC was incredibly strong, but even they weren't enough to deal with this situation, and now we're on our own!", you can demonstrate the challenges and stakes of the scenario. But by keeping the sequence relatively short and planning for these specific elements you can do a lot to protect against the risk of the NPC stealing the spotlight from the players.

But don't send the GMPC as a companion for very long. Making combats arbitrarily difficult and then adding an arbitrarily powerful GMPC isn't all that different from just making the combats arbitrarily easier, except that in the former case the players are much less important and have much less to do.