underwater

[Vipersfang]

I`m getting a urge to write a underwater adventure but i need some advice.

1. what unique creatures would you recommend for 4 level 6 characters?

2. what plot could i use?

[Loreguard]

You could dive into the old stories.

A prince of a kingdom falls for the daughter of a king of and undersea kingdom. The undersea kind does NOT like grounders/airbreathers.

Your job if you choose to accept it is to un-kidnap the princess from her father and deliver her to the prince.

There might be call or need for some combats to be non-lethal, because there is hope to turn the marriage into an alliance, so you can't just go killing all the sea-king's population in order to take possession of the princess again.

Note I use the potentially -improper- references with regards to treating the princess on purpose... because maybe not everything is completely aboveboard on everything that is happening. Perhaps the Prince isn't actually the one the princess fell in love with, but instead the Prince's non-publicized twin brother. But the brother/prince found out and wants to leverage this to expand his realm into the sea? Or maybe it is true love for the Prince, but the prince is young and is being manipulated by a Regent who plans to eventually take the kingdom away from the prince before he has his 21st birthday.

Or... reverse the roles/genders, and have the prince be the undersea prince, being woo'd by a terrestrial princess. (The undersea can still be the dad... they always are the bad guy in these stories, although you could swap genders there too, if you want to make it a jealous mother unwilling to let their son lower themselves to consort with the grounders.

Alternate plot:
Adventurers hired to recover family heirloom, relic, or other important item (maybe even the bodies of a family) which were lost at sea, because of their importance. This means they get sent out to last place the ship was seen and track it down to where the ship went down.

The investigation could lead them to the creature responsible, which might be one or more Avarek. There could be giant sharks or eels guarding the site of the wreckage. Perhaps there could be signs of some Azarketi having looted the wreckage of some of the items being searched for. And that could lead to a trail with a Giant Squid or Jellyfish guardian, and some NPC Azarketi which might be able to be negotiated with if you help them with some other encounter/creature in the area, causing them issues.

I'd suggest using a mix of natural-ish animals, (eels, sharkes, squids) beasts/abominations/aberrations such as Ahuizotl, Alghollthu, or Chuul, as well as potentially something like Azarketi or other amphibious NPC race that might be able to interact with to ask questions, and gather information via diplomatic channels. You could also surprise them with an encounter in an enclosed air pocket, where they aren't swimming around in that encounter.

[Taja the Barbarian]

I would think a 'proper' underwater adventure would likely be extremely rough for level 6 characters:

Chapter 9: Playing the Game / Encounter Mode / Special Battles / Aquatic Combat wrote:

Source Core Rulebook pg. 478 3.0

Use these rules for battles in water or underwater:

You’re flat-footed unless you have a swim Speed.
You gain resistance 5 to acid and fire.
You take a –2 circumstance penalty to melee slashing or bludgeoning attacks that pass through water.
Ranged attacks that deal bludgeoning or slashing damage automatically miss if the attacker or target is underwater, and piercing ranged attacks made by an underwater creature or against an underwater target have their range increments halved.
You can’t cast fire spells or use actions with the fire trait underwater.
At the GM’s discretion, some ground-based actions might not work underwater or while floating.

And that's not even talking about the simple need to actually breathe, which will probably eat up some top-tier resources at level 6.

Group composition will probably make a huge difference here: For example, the Axe wielding Gold Dragon Instinct Barbarian from my AoA playthrough would likely just prefer to stay home...

[Guntermench]

Underwater at 6 would be mildly frustrating for anyone not an Azarketi or Undine.

[HumbleGamer]

Song of the deep could be pretty interesting for the characters to have.

It's also pretty cool in terms of possible flavor, and it's nice because it doesn't force players to choose a specific ancestry or heritage ( which always sucks) because of mechanics and advantages.

[Malk_Content]

For plot that doesn't restrict people's choices. An Alkenstar inventor has created what she calls an Atmosphere Engine, it creates a bubble of air sufficient to go under water. Greater depths reduce the size of this bubble and the machine is bulky.

The invention was used by a team of non adventurers to explore some underwater ruins, but for unknown reasons haven't resurfaced on schedule. The pcs are tasked with taking the other remaining prototype into the ruins to discover what happened (and hopefully rescue) the initial party.

Have areas where the engine can't fit until the party does some underwater exploration (say they might need to swim up to a ledge to activate an elevator.) If the ruins were actually a temple to some dark entity you could create fun things like zombie sharks that launch themselves out the water into the air bubble that's small enough to make even a zombie sharks 10ft ground speed scary etc.