The Clashing Gates
A boarding battle between rocks that hate ships.
Style: Kinetic trireme gauntlet for 6 level-8 PCs, mixing helm checks, boarding fights, and hard navigation choices.
Win: Thread the Symplegades with the ship intact enough to sail and the Titan-kin boarding rite broken.
Lose: The rocks learn the ship's name, crush the route shut, and leave survivors stranded on living stone.
Maguffin: Bronze Dove of Phineus · Ally: Kyane the Blue Oar · QG: Captain Philon of the Mist Trireme
"Send the dove first, count the heartbeat second, and trust the oar that pulls when the stones inhale."
Major Beats
- Philon's confidence cracks when the rocks answer the trireme's old name.
- The first omen is useful but not complete.
- Boarders attack the ship's timing more than its crew.
- The finale rewards choosing exactly when to fight and when to row.
Difficulty
| Tier | Adjust |
|---|
| As Written ★ | 6 PCs · APL 8 |
| Library Standard | 6 PCs · APL 8 — Identical to As Written — this guide’s baseline is already 6 PCs at average level 8. |
| Easier | APL 4–6: reduce minion counts ~30%; DCs −2; boss loses one recharge or legendary option. |
| Harder | APL 10–12: boss HP +25–35%; +1 legendary action; add a lieutenant or extra wave. |
Captain Philon of the Mist Trireme hooks the party. Maguffin Bronze Dove of Phineus pays off in the finale against Brontes Gate-Heir . Recruit Kyane the Blue Oar along the way.
Creature / Enemy List
| Creature | Counts / Notes |
|---|
| Rock-Grappler Raider | med · hard · CR 3 · Boarding skirmisher |
| Tide-Ogre Bosun | med · hard · CR 5 · Deck breaker |
| Stone Scion of the Gates | med · hard · CR 6 · Titan-kin controller |
| Brontes Gate-Heir | med · hard · CR 10 · Boss boarder |
| Kyane the Blue Oar | 1 · 1 · Recruit Enc. 1 |
DM Tips
- As Written ★ — 6 Players, Average Level 8: Baseline for this guide. Numbers, DCs, and win tracks assume six PCs at average level 8.
- Easier: APL 4–6: reduce minion counts ~30%; DCs −2; boss loses one recharge or legendary option.
- Harder: APL 10–12: boss HP +25–35%; +1 legendary action; add a lieutenant or extra wave.
Maguffin reminder: Check Enc. 3 payoff on the item card (page 3/4). Reward players who keep the object in hand.
Ally snapshot
Kyane the Blue Oar
- RECRUITMENT (Enc. 1). Let her call cadence during the first crush, or beat her honest in a rowing contest.
- Aid. Acts on party initiative when recruited; prefers nonlethal when asked.
Encounter 1 — Dove Before Oars
Approach the breathing rocks, test the current, and decide whether to trust omen, crew, or speed.
- Navigation challenge: 5 successes before 3 failures at DC 15 using vehicles, Athletics, Perception, or Survival.
- The Bronze Dove grants advantage and tells which rock will move first.
- Recruit Kyane by honoring her cadence; she grants one ship-check reroll per later encounter.
- Failure damages a ship zone or starts Encounter 2 with Rock-Grapplers already aboard.
- Tip: Medium Humanoid, Neutral · Recruitable Ally · Champion rower and boarding repeller
- Tip: RECRUITMENT (Enc. 1). Let her call cadence during the first crush, or beat her honest in a rowing contest.
- Tip: Aid. Acts on party initiative when recruited; prefers nonlethal when asked.
Encounter 2 — Boarders From Both Stones
Titan-kin leap from both cliffs to pin the trireme in place while the gates start closing.
- At initiative 20, choose: rocks close 20 ft, a ship zone takes damage, or two raiders board.
- Non-combat option: beat the Tide-Ogre's cadence with Performance/Athletics DC 16 to stall one bridge.
- Repairing an oar bank takes an action and tools or Strength DC 15; Kyane makes it a bonus action once.
- The Bronze Dove can identify the Stone Scion sustaining the anchor chant.
- Tip: Medium Humanoid, Neutral · Recruitable Ally · Champion rower and boarding repeller
- Tip: RECRUITMENT (Enc. 1). Let her call cadence during the first crush, or beat her honest in a rowing contest.
- Tip: Aid. Acts on party initiative when recruited; prefers nonlethal when asked.
Encounter 3 — The Count Between Clashes
Run the final gap while Brontes lands on deck and the stones try to remember the ship forever.
- Seven-count clock: each round PCs assign helm, oars, repairs, and boarder control before the rocks move.
- Spend the Bronze Dove to cancel one rock-clash or reveal the anchor-chain's weak link.
- Win by cutting the anchor-chain and clearing the gap, forcing Brontes overboard, or bargaining with his honor.
- If the ship reaches 3 broken zones, it still escapes only if PCs jettison cargo or beach on a living rock.
- Tip: Medium Humanoid, Neutral · Recruitable Ally · Champion rower and boarding repeller
- Tip: RECRUITMENT (Enc. 1). Let her call cadence during the first crush, or beat her honest in a rowing contest.
- Tip: Aid. Acts on party initiative when recruited; prefers nonlethal when asked.
DM Callouts
- Medium Humanoid, Neutral · Recruitable Ally · Champion rower and boarding repeller
- RECRUITMENT (Enc. 1). Let her call cadence during the first crush, or beat her honest in a rowing contest.
- Aid. Acts on party initiative when recruited; prefers nonlethal when asked.
- Medium Humanoid, Neutral · Recruitable Ally · Champion rower and boarding repeller
Extra Encounter Detail (from session guide)
- Tip: Keep page-3 creature AC/HP lines visible while resolving Enc. 3.
- Tip: Favor non-combat paths in Enc. 1–2; Enc. 3 should still feel Hard.
Quick combat reference
- Kyane the Blue Oar — AC 16 | HP 83 | Speed 30 ft. · Medium Humanoid, Neutral · Recruitable Ally · Champion rower
- Rock-Grappler Raider — AC 16 | HP 74 | Speed 30 ft. · Medium Creature · CR 3 · Boarding skirmisher
- Tide-Ogre Bosun — AC 15 | HP 118 | Speed 30 ft. · Medium Creature · CR 5 · Deck breaker
- Stone Scion of the Gates — AC 17 | HP 132 | Speed 30 ft. · Medium Creature · CR 6 · Titan-kin controller
- Brontes Gate-Heir — AC 18 | HP 210 | Speed 40 ft. · Large Creature · CR 10 · Boss boarder · Boss
Additional DM notes
- Motivation.** He must prove a safe western route before the fleet commits to the passage.
- Secret.** He once lost a crew here and still hears their oars in the fog.
- Hard rule.** He will sacrifice cargo before crew, but not the ship's dove unless convinced it saves everyone.
- Appearance:** Palm-sized bronze dove with one real white feather in its throat.
- Handout.** "If it returns with clipped wings, row. If it returns whole, pray faster."
- Enc. 1–2.** Launch it to scout currents, granting advantage on one vehicle (water) or Perception check.
- Enc. 3.** Its wingbeat names the safe count; spend it to cancel one rock-clash or expose the Titan-kin anchor.
- 12 (+1)**STR**14 (+2)**DEX**12 (+1)**CON**12 (+1)**INT**14 (+2)**WIS**16 (+3)**CHA
- Role:** Champion rower and boarding repeller
- RECRUITMENT (Enc. 1).** Let her call cadence during the first crush, or beat her honest in a rowing contest.
Pacing helpers
- Enc 1: End by ~45–50 min; if stuck, telegraph the non-combat path once.
- Enc 2: Spend recruitment / maguffin early so Enc 3 is not a blank check.
- Enc 3: Keep Hard, not Deadly — drop a minion wave before a TPK spiral.
- Table tip: Restate win condition when HP dips; players often forget the maguffin.
NPC / ALLY
Captain Philon of the Mist Trireme
- He must prove a safe western route before the fleet commits to the passage.
- He will sacrifice cargo before crew, but not the ship's dove unless convinced it saves everyone.
Kyane the Blue Oar
- Recruit Enc. 1: Let her call cadence during the first crush, or beat her honest in a rowing contest.
- AC 16 · HP 83 · Oar-staff +7 to hit, 14 bludgeoning; grants one reroll on a failed ship check.
Remember
- Thread the Symplegades with the ship intact enough to sail and the Titan-kin boarding rite broken.
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