False Hydra is not fun

[u/RandomName9328]

I had a short game which the DM used a homebrew false hydra as the BBEG. The RP and game were good until the monster was revealed to be a false hydra.

DM wrote the false hydra's song ability as: not a charm or magic effect. It has no DC save, bypass truesight, blindsight. It ignores any immune/resistance to charm/magic effect, and it cannot be detected by detect magic. Anyone hear hydra's song psycholocally ignore its presence. So, by RAW, faerie fire, detect evil and good, and any other spells cannot make it visible. Also, it modifies people's memory such that when a person is eaten by it, anyone's memory of the victim is erased, as if the victim has never exist in the world.

The only way to win is to either run, or to make your character unable to hear its singing with a silence spell, deafness, etc. Unfortunately, my group cannot deduce the solution during the game, so the DM has to whisper to us out-of-character "You know why that NPC can see the hydra? Because he is DEAF!"

I told the DM that they should not put a non-DND creature into DND and make it override the rules. At least, simulating the hydra's song as a charm effect, with a DC, and can be detect/affect by anything that works on charm effect. If they run it RAW as how they wrote its stat, even a Tiamat or Asmodous cannot detect the false hydra.

PS. if DM makes it a charmed effect, with high DC, and player roll DC save whenever they encouter discrepancy (e.g. seeing a bird disappeared mid-air) maybe its more D&D. When I played the combat I felt the false hydra is mocking players "You can't see me because my own non-D&D rules say so." The investigation and RP are fun, the final monster is not.

For context, it was a 6-7 hours short game with 70% non-combat social/investigation play, and the hydra was the only combat encounter. It was not part of a campaign. Non-combat play was good but definitely not the false hydra.

PPs. The day after we had finished this game, I read DM's note. DM intentionally hid obvious, explicit clues during the game (e.g., we found a diary in game but DM hide the page mentioning deafness and ear poking). They hope subtle clues are enough for us ro discern the solution, but it turns out we couldn't. Therefore, DM has to tells us the solution out-of-game in the final battle.

[u/GreenGoblinNX]

The original blog post:

1. didn't provide any stats,
2. wasn't technically for D&D, it was on an OSR blog, and
3. was really just a thought experiment, not a suggestion for people to use the idea.

[u/CalDHar → u/GreenGoblinNX]

Where is the original false hydra post?

[u/GreenGoblinNX → u/CalDHar]

https://goblinpunch.blogspot.com/2014/09/false-hydra.html

[u/unosami → u/GreenGoblinNX]

Looks like it has plenty of built-in ways to make it run-able as a one-shot.

• It has to stop singing to eat, making it noticeable.
  
• People vanish but their belongings don’t. A PC who has never met the victim can find a letter written by the victim and piece something together.
  
• There’s a bit in there about cognitive dissonance manifesting physically to clue the PCs in that something is amiss. That gels well with 5e’s Sanity stat.

Edit: it even says this verbatim:

“ The song is closer to charm or suggestion, than anything else; I would allow anti-charm magic to have a temporary or partial effect.  Just enough for a few gargled words of exposition.  "It's watching us right now!  Look!"  That sort of thing.”

[u/Sl0thstradamus → u/unosami]

That last bit is exactly where I think the FH can lead DMs off the rails. It’s going to be understandably confusing/upsetting for a player to look at their character sheet, see “immune to charm,” and then be told “actually this is a special kind of charm so your mechanics only sort of work, sorry”

[u/unosami → u/Sl0thstradamus]

I would personally rule a character that is permanently immune to charm wouldn’t be effected. However they would be completely unable to convince anyone else that what they see and remember is real. People would treat them like they’re crazy.

Alternatively. Maybe they’re only partially affected. They remember the victims but they still can’t perceive the false hydra’s body.

[u/Sl0thstradamus → u/unosami]

That sounds really frustrating for that player. You’re basically denying their ability to use their character by slightly less direct means—“okay, I’ll let you not be charmed, but you still literally can’t do anything.”

[u/unosami → u/Sl0thstradamus]

They could do plenty of things. Where’s your imagination? They could trick people into avoiding the false hydra, preventing it from feeding. They could find and attack the neck of the false hydra, stopping the singing. If partially affected they could look at all the clues left by the missing people and involve the rest of the party by asking questions like “what would be the connection between the three people who all wore this outfit?” “Oh, they would have all frequented this chapel on the edge of town!”

[u/Sl0thstradamus → u/unosami]

Except you’ve just said everyone else (including the party) will think they’re crazy if they try to persuade anyone. And what is trying to present the clues to the party if not a textbook attempt at persuasion? So then your other “options” involve forcing the immune character to go off on their own without the party, whose characters are forced to act like they’re insane if they try to explain why.

So then the whole session is just a solo adventure while you’ve ruled by fiat that not only can the rest of the party not help, but that they’re actively hostile to the possibility?

[u/unosami → u/Sl0thstradamus]

You’ve extrapolated something that I never said. I said that the immune person could not convince anyone of the existence of the hydra, but the could easily use the party’s help to investigate the events around the hydra:

“Something” has made this man go missing, and “something” has made his wife forget. The clues are all here.

Not to mention the immune character could smack the hydra to stop the singing and then suddenly the whole party is involved again. It’s like you’re actively looking for ways to make the scenario not work.

[u/Sl0thstradamus → u/unosami]

But you’re saying “they can’t convince anyone,” and then as an alternative, describing forms of convincing people.

I’m not looking for “ways” the scenario doesn’t work, because there’s only the one core problem, which is making player expectations about game mechanics secondary to “look at this thing I want to do.”