Merfolk Skirmisher

Merfolk allies are the natural framing if the party has earned a coastal community's trust, rescued a tide-pool village from a sahuagin raid, or signed a treaty with a sea hag's old enemies. A skirmisher escort is what a merfolk leader sends when they want to help but not commit. Two or three of them shadow the party's boat, scout the channel ahead, and surface when needed.

Use them out of combat for what no one else in the party can do: scouting underwater wrecks, recovering drowned cargo, swimming a message ten miles down the coast in an hour. The 40 ft. swim and Amphibious trait make them a logistics multiplier in any aquatic adventure. They speak Common, so negotiation is direct, but they think in tides and currents and the party should feel that gap.

In combat, position them in the water and keep them there. Ocean Spear from 60 ft. away targets whichever enemy the party calls out, the speed reduction stacks on enemy melee chasers, and the spear returns to hand so they never run out of throws. Three skirmishers in a flooded room can keep a sahuagin warrior from ever closing on the cleric. On dry ground they are nearly useless; the party will need to carry water buckets, flood the room, or accept the merfolk waiting at the shoreline.

What they refuse: leaving the coast, fighting whales or dolphins for any reason, ambushing a vessel flying a peace banner under coastal law. They take their old laws seriously and the party should learn the laws before asking.

Have one of the skirmishers gift a single spear to the PC who saved their village. The spear does not return to that PC's hand; it is just a spear. The gift is the point.

A merfolk skirmisher is a coastal patrol with a magical javelin. The encounter only works if the party is at least partly in or near water. With a 10 ft. walk speed and a 40 ft. swim, this fish-out-of-water becomes one of the worst threats in the SRD on a riverbank, dock, or flooded ruin and one of the most embarrassing on a dry road. Pick the terrain or do not run the encounter.

Open from the water at range. Ocean Spear is the entire kit: +2 to-hit, range 20/60 ft., 3 piercing plus 2 cold, and the spear magically returns to the merfolk's hand after every ranged attack. The hit also drops the target's speed by 10 ft. until the end of its next turn. That speed reduction is the actual threat. A patrol of four skirmishers throwing every round can stack the slow on a melee fighter trying to wade across a stream and keep them there indefinitely. The damage is irrelevant; the kiting is what kills.

Run them as a school. Three to six skirmishers swimming in a loose line, throwing in a rolling volley so at least one spear lands per round, then diving and surfacing 30 ft. away in any direction. Amphibious means they breathe air and water both, so they can pop up under a dock, behind a moored boat, or inside a flooded temple antechamber. The party that tries to swim after them loses; the party that holds the shoreline and forces them to come ashore wins, because the skirmishers' walk speed is 10 ft. and they are AC 11 with 11 HP.

A merfolk patrol does not die for the reef. Once two of the school are down or the party brings out area-of-effect spells, the survivors dive deep and disappear. They report back to a tribe leader. The next encounter has names.

Have one of them surface, throw a spear at the party's loudest member, and shout one word in Primordial (Aquan) before diving. The party will spend a session figuring out what it meant.