Riddles at the Peak
One-Shot · 4–5 Players · Average Level 7 · ~3.5 Hours · Greek Mythology
📜 Session Summary
| Style Mythic Quest — Social / Avoidance / Boss Combat |
| Win Condition Pacify or defeat the sphinx Arkteia; re-open the mountain trade routes through Theron |
| Players 4–5 × Level 7 (see Difficulty Scaling for APL 5–9) |
| Est. Duration 3–3.5 hours |
| Encounters 3 total · Enc. 1 & 2 fully avoidable via skill checks or roleplay · Enc. 3 is a hard boss fight with a non-combat win condition |
| Setting Greek Mediterranean — open sea aboard a trireme, forested island crossroads, crumbling mountain-top oracle temple |
| Hero NPC Atalanta (legendary huntress, favored of Artemis) — recruitable in Encounter 2 |
Description
The ancient gynosphinx Arkteia has awakened beneath the summit ruins of Mount Theron, terrorizing merchant vessels and devouring those who cannot answer her riddles. The sea captain Nikias of Piraeus — sole survivor of a previous expedition — hires the party, hands them a water-stained parchment recovered from the wreck of his last crew, and offers them passage aboard his trireme. He believes the parchment is the key to surviving what he could not.
Handout — The Parchment
What Nikias knows: "A scholar who went to Theron before me. He didn't come back — but his notes did, sealed in a jar. I can't read the old script, but one of the dockworkers said the circles meant something about asking."
Encounter 3 Payoff: Presenting this parchment to Arkteia causes her to pause before attacking and invoke the Right of the Riddled — she poses three riddles before any violence begins. Without the parchment, combat starts immediately; riddles may only be offered mid-fight via her Riddle of Fate ability.
Key NPCs
Nikias of Piraeus — Quest Giver
Aging sea captain, sole survivor of the sphinx's last encounter with mortals. Missing two fingers on his left hand. Offers passage on his trireme and 500 gp for a resolution. Secret: The sphinx spared him — and he has no idea why. He is deeply ashamed of this and won't discuss it.
Atalanta — Recruitable Ally (Encounter 2)
Legendary huntress, virgin warrior, favored of Artemis. Encountered in a tense standoff with the centaur chieftain Eurytion, who has stolen her silver arrow. Will join the party if they help recover it. Secret: Artemis tasked her to watch the sphinx and intervene only as a last resort — she is more conflicted about this mission than she admits.
Arkteia — Antagonist / Boss
Ancient gynosphinx, awakened by miners disturbing the ruins of her resting place. Not purely malevolent — she tests mortals because she believes only the wise deserve passage. Secret: She yearns to return to her slumber. Violence is genuinely her last preference; she is simply too proud to say so.
Creature / Enemy List
| Creature | Easy | Medium | Hard | Notes |
|---|---|---|---|---|
| Siren | 1 | 3 | 4 | Encounter 1; fully avoidable via skill challenge |
| Centaur | 2 | 4 | 6 | Encounter 2; avoidable via roleplay/skill checks |
| Eurytion, Centaur Chieftain | — | 1 | 1+ | Encounter 2; avoidable; does not flee |
| Manticore | 1 | 2 | 3 | Encounter 3; guardian creatures for the sphinx |
| Arkteia (Sphinx) | 1 (adjusted) | 1 | 1 (buffed) | Encounter 3 boss; see Difficulty Scaling |
| Atalanta | — | — | — | Recruitable ally in Enc. 2; fights with party in Enc. 3 |
Major Beats
- The Captain's Commission: Nikias hires the party at a coastal tavern, hands over the parchment, and offers passage on his trireme. He warns them flatly: "She will ask you something. Answer well."
- The Siren Straits (Encounter 1): Three Sirens perch on sea rocks near the island approach, singing. The party can navigate around them, counter their song, plug their ears — or fight.
- The Crossroads Standoff (Encounter 2): A centaur warband blocks the mountain road. Atalanta is in a bristling standoff with chieftain Eurytion over her stolen silver arrow. Negotiate, trick, fight — and recruit Atalanta if they help her.
- The Ascent: The mountain path to the temple. If Atalanta joined, she briefs the party on the sphinx's known behaviors and the temple layout. A key moment for roleplaying the party's plan.
- The Riddle at the Peak (Encounter 3): Arkteia and her two Manticores await. The parchment can trigger the Right of the Riddled. Players may defeat her, answer three riddles, or solve a logic puzzle to end the threat.
- Resolution: The party returns to Nikias — with proof of defeat, a signed compact of passage, or a secret the sphinx chose to share only with those who earned her respect.
Encounter 1 — The Siren Shores
Overview
As the trireme rounds Theron's rocky northern headland, three Sirens become visible on the wave-lashed rocks below the cliffs. Their song carries across the water immediately — beautiful, ascending, and immediately unsettling. Nikias (on the helm) goes pale and begins steering away, shouting at the party to do something. Six NPC crewmen are present; they have no earplugs and will begin walking toward the rail if the song is not countered.
- Style: Avoidance Skill Challenge / Optional Combat
- Win Condition: Pass the Siren Shores without ship damage or crew lost; reaching the island's beach safely
Creatures (combat only)
- 3× Siren — CR 3 (700 XP ea.)
Avoidance Summary
- Skill challenge: 3 successes before 3 fails
- Or: RP-based creative solutions
- Or: Outright flee (wide arc, +1 hour travel)
🗺 Terrain & Features
Open sea / rocky shore approach — Trireme deck ~60×20 ft; sirens on rocks ~60–100 ft distant
- Sea rocks (difficult terrain to reach — DC 12 Athletics to climb without slipping prone)
- Crashing waves: any creature knocked prone within 5 ft. of the ship rail must succeed DC 12 STR save or fall overboard (action + DC 14 Athletics to climb back)
- Trireme sails: AC 10, 30 HP. Destroyed sails cost 1 extra hour of rowing to reach shore (short rest forfeited before Enc. 2)
- 6 NPC crewmen: no saves vs. Alluring Song without earplugs; begin drifting toward the rail on failed saves
Harder: 4 Sirens; a crew member moves 15 ft. toward the rail at initiative 20 each round regardless of saves; Sirens only flee if reduced below 10 HP simultaneously.
Mechanics
Avoidance Skill Options
- DC 14 WIS (Perception) — Spot the Sirens early enough to shout a warning before the song takes effect. Success grants advantage on the first subsequent check for one other party member.
- DC 14 WIS Save — Resist the Alluring Song long enough to act deliberately this round. Failure: character uses movement to approach the ship's rail this turn (does not provoke Siren reactions).
- DC 12 STR (Athletics) or DEX (Acrobatics) — Adjust rigging, brace sails, or physically restrain a charmed crewmember before they reach the rail.
- DC 15 CHA (Performance) — Counter the song with an instrument or powerful voice. Success: all crew and party members have advantage on WIS saves until start of this character's next turn. Failure: Sirens are drawn to this character (they focus attacks on them in combat).
- DC 14 INT (Navigator's Tools) or WIS (Survival) — Chart a wide-arc course around the rocks entirely. Success counts as two successes. Failure: the ship drifts into range of a fourth hidden Siren (add 1 to combat, or add 1 failure to the challenge).
- Improvised earplugs: Rope fiber, wax from candles, cloth — any party member who takes a full action to prepare plugs for themselves and one adjacent ally is immune to Alluring Song. They cannot hear verbal commands and must use Signals (DC 10 INT) to coordinate. No check required.
- Bribery/Offering: Sirens have INT 13 and understand Common. A character who speaks to them and offers something beautiful (jewelry, a poem recitation, a rare object worth 50+ gp) may attempt DC 16 CHA (Persuasion). Success = one Siren withdraws. Each success removes one Siren from the challenge or combat.
- DM-only — Fire Vulnerability: Sirens take double damage from fire (players don't know this). A fire attack, thrown torch, or fire cantrip that hits draws a visible flinch-and-retreat; a clever player noting this should be rewarded with the knowledge.
- Full Retreat: Nikias can sail wide around the point at any time. This costs 1 hour of travel time and guarantees no combat, but means no Short Rest before Encounter 2 (the delay puts the party under pressure to reach the sphinx before nightfall).
- Sirens begin on rocks (60–80 ft. from the ship); they have Fly 50 ft. and will close in rounds 1–2.
- A Siren that takes 20+ damage in a single hit immediately dives into the water and does not return (retreat, not dead).
- At initiative 20 each round, each un-plugged NPC crewman makes DC 14 WIS save or moves 15 ft. toward the nearest rail.
- A crewman at the rail goes overboard at the start of their following turn unless grappled (DC 12 STR) by a party member as a reaction or bonus action.
- Sirens use Captivating Dirge on any party member adjacent to the ship rail first.
Resolution
Creature Cards
Siren
Medium Fey, Chaotic Neutral · CR 3 (700 XP)
AC 13 | HP 52 (8d8+16) | Speed 30 ft., Fly 50 ft., Swim 40 ft.
Saves: WIS +3, CHA +7 | Skills: Perception +3, Performance +9
Vulnerabilities: Fire | Senses: Darkvision 60 ft., Passive Perception 13
Languages: Common, Primordial
Alluring Song. Any creature within 60 ft. that can hear the Siren must succeed DC 15 WIS save at the start of each of its turns or be Charmed. While Charmed, the creature must use its movement each turn to approach the nearest Siren and cannot willingly move away from it.
Multiattack. Two Talon attacks.
Talon. +5 to hit, reach 5 ft. Hit: 7 (1d6+4) slashing.
Captivating Dirge (Recharge 5–6). One creature within 120 ft. that can hear makes DC 15 WIS save or is Stunned until end of its next turn. On failure, a creature adjacent to a ship rail or cliff edge falls from that edge.
Haunting Melody. When hit by an attack, the Siren sings a discordant note. The attacker makes DC 13 WIS save or has disadvantage on all attack rolls until the end of its next turn.
Encounter 2 — The Centaur's Crossroads
Overview
The forest road to Mount Theron's pass is blocked. Four Centaurs stand in a loose line, lances leveled. Their chieftain, Eurytion, holds a silver arrow raised overhead in one fist. Across the road from him — arrow nocked, jaw set — stands Atalanta, legendary huntress, favored of Artemis. Neither side has moved in some time. Both parties look quietly relieved to have a new variable arrive.
- Style: Social Encounter / Avoidance Challenge with Optional Combat
- Win Condition: Gain passage up the mountain road; Optional: recruit Atalanta as an ally
Creatures (combat only)
- 4× Centaur — CR 2 (450 XP ea.)
- 1× Eurytion — CR 4 (1,100 XP)
Hero NPC Present
- Atalanta — not yet an ally; armed and ready
- She will NOT fight the whole herd alone; she needs the party's help to act
🗺 Terrain & Features
Forest crossroads — ~80×60 ft. clearing; narrow road 10 ft. wide through dense olive trees
- Dense olive tree line on both sides: difficult terrain for Large creatures (Centaurs); Half Cover for Medium/Small creatures ducking branches
- Crumbling stone well (center of clearing, 10 ft. diameter, 4 ft. tall): Three-Quarters Cover for crouching Medium or smaller creatures
- Road (north/south): only 10 ft. wide — Centaurs charging down it can only hit creatures in the road, not those who step into the tree line
- Eurytion holds the Silver Arrow aloft — if he drops it (death, incapacitation, or chooses to), Atalanta immediately looses her nocked arrow at him (her attack, not the party's)
Harder: 6 Centaurs; 2 reinforcements emerge from the tree line on Round 2; Eurytion has 2 uses of Legendary Resistance.
Mechanics
Situation Brief
Eurytion: Regards Arkteia as sacred — a divine guardian of the mountain. He will not let armed strangers pass without proof they will approach her respectfully. He stole Atalanta's arrow for leverage; he knows she'll destroy him the moment he doesn't have it. He will negotiate if shown wisdom, respect, or given a compelling reason to believe the party won't desecrate the sphinx's temple.
Atalanta: The silver arrow was a gift from Artemis herself. She is furious but controlled. She will not attack into a melee she can't win alone. She'll help the party if they help her — and she knows the mountain and the sphinx's habits better than anyone present.
Skill Options — Convincing Eurytion
- DC 13 CHA (Persuasion) — Appeal to centaur honor: promise to face the sphinx in the "old way" (riddle-challenge, not brute force). Eurytion respects this; he demands a vow and steps aside.
- DC 14 INT (History or Religion) — Correctly cite the ancient protocol for approaching a sphinx (present a petition, speak her name, invoke right of passage). This impresses him; +2 to next Persuasion check, or counts as one success in the challenge.
- DC 14 CHA (Intimidation) — Call Eurytion a coward for stealing a weapon instead of fighting. On success, his pride forces him to return the arrow and prove himself differently. On failure: combat begins immediately.
- DC 12 DEX (Sleight of Hand) — Steal or swap out the arrow while Eurytion is distracted (requires a simultaneous distraction: DC 13 CHA Performance or DC 14 CHA Deception from another party member).
- Auto Show the Parchment — Eurytion recognizes the three-circle symbol as the ancient Compact of Passage. He lets the party through immediately but does NOT return the arrow unless also separately convinced or tricked.
Once recruited, she describes the temple layout in Encounter 3 (DM: hand-wave a brief tactical description of the column ring and shattered altar). She mentions quietly: "She will ask you three things. Answer truly, all three. That is what the old stories say." — this is a direct hint toward the parchment's message, even if the party hasn't read it carefully.
- Trial of Strength: Eurytion allows one party member to wrestle a centaur (best 2 of 3 contested STR Athletics checks; centaur +4). Win = passage granted, honor satisfied, arrow returned. Lose = passage refused; must find another approach.
- Wine Tribute: Centaurs famously love wine. Offering a wineskin or flask of quality spirits (worth 10+ gp) gives advantage on any subsequent Persuasion check with Eurytion.
- Invoke Artemis: A party member who worships Artemis, has a holy symbol of her, or can cast Thaumaturgy to create a silver light effect can invoke her name. Atalanta will immediately vouch for them to Eurytion, reducing Persuasion DC to 10.
- Round 1: Eurytion uses War Shout (bonus action) — all Centaurs have advantage on attacks until start of his next turn. He then charges the nearest armored party member (pike + hooves multiattack).
- Centaurs prioritize charging (Charge trait); they try to knock the heaviest party members prone in the road and follow up with hooves.
- If Eurytion drops the arrow (falls unconscious, drops it to gesture, etc.): Atalanta immediately fires at him — deal her shortbow damage openly. She then calls out to the party: "I owe you nothing yet — but help me and I'll change that." She will join at this moment if any party member acts to protect her or acknowledges her.
- Centaurs surrender or scatter at 25% HP if Eurytion is incapacitated. Eurytion fights to 0 HP.
Resolution
- Eurytion's saddlebag: 3× Javelins of Lightning (on hit, deals +1d6 lightning damage — single use each; DM discretion on survival).
- A centaur scout's worn map of the mountain road — shows two narrow side paths leading to hidden entrances on the east and west sides of the summit temple ring (Encounter 3 terrain flavor).
Creature Cards
Centaur
Large Monstrosity, Neutral Good · CR 2 (450 XP)
AC 12 | HP 45 (6d10+12) | Speed 50 ft.
Skills: Athletics +6, Perception +3, Survival +3
Charge. If the centaur moves ≥ 30 ft. straight toward a target and hits with a Pike attack, the target must succeed DC 14 STR save or be knocked prone.
Multiattack. One Pike and two Hooves.
Pike. +6 to hit, reach 10 ft. Hit: 9 (1d10+4) piercing.
Hooves. +6 to hit, reach 5 ft. Hit: 11 (2d6+4) bludgeoning.
Javelin. +6 to hit, range 30/120 ft. Hit: 7 (1d6+4) piercing.
Eurytion, Centaur Chieftain
Large Monstrosity, Lawful Neutral · CR 4 (1,100 XP)
AC 14 (natural armor) | HP 95 (10d10+40) | Speed 50 ft.
Saves: STR +7, CON +6 | Skills: Athletics +7, Intimidation +4, Perception +4, Survival +4
Charge. If Eurytion moves ≥ 30 ft. toward a target and hits with Pike, target makes DC 16 STR save or is knocked prone and pushed 10 ft.
Herd Commander. Centaurs within 60 ft. have +2 to their AC while Eurytion is conscious.
Multiattack. One Pike and two Hooves, or two Javelins.
Pike. +7 to hit, reach 10 ft. Hit: 11 (1d10+5) piercing.
Hooves. +7 to hit, reach 5 ft. Hit: 12 (2d6+5) bludgeoning.
Javelin. +7 to hit, range 30/120 ft. Hit: 8 (1d6+5) piercing.
War Shout (Recharge 5–6). All Centaurs within 60 ft. have advantage on attack rolls until start of Eurytion's next turn.
Trample. When a creature within 10 ft. moves away from Eurytion, he may make one Hooves attack against it.
Atalanta
Medium Humanoid (Human), Neutral Good · CR 6 (2,300 XP) — Recruitable Ally
AC 15 (leather armor) | HP 78 (12d8+24) | Speed 35 ft.
Saves: DEX +8, WIS +6 | Skills: Acrobatics +8, Athletics +5, Nature +5, Perception +9, Stealth +8, Survival +6
Languages: Common, Elvish, Sylvan
Favored of Artemis. Atalanta ignores difficult terrain in natural environments. Her ranged attacks suffer no disadvantage at long range. She has advantage on WIS (Perception) checks.
Hunter's Instinct. Atalanta always knows the HP category (Healthy/Bloodied/Critical) of any creature she can see.
Multiattack. Three attacks: two Shortbow and one Shortsword, or three Shortbow.
Shortbow. +8 to hit, range 80/320 ft. Hit: 8 (1d6+5) piercing.
Shortsword. +8 to hit, reach 5 ft. Hit: 8 (1d6+5) piercing.
Silver Arrow (1/day). +8 to hit, range 80/320 ft. Hit: 8 (1d6+5) piercing + 10 (3d6) radiant damage. Ignores resistance to piercing damage. Target has disadvantage on all attacks until start of Atalanta's next turn.
Hunter's Mark. Mark one creature. All of Atalanta's hits against it deal +3 (1d6) extra damage. Lasts until target dies or she marks another.
Encounter 3 — The Sphinx of Mount Theron (Boss)
Overview
The summit of Mount Theron holds a ring of crumbling marble columns — the ruins of an ancient oracle temple, open to the stars. Arkteia sits on a shattered altar stone like a queen on a broken throne, wings folded, golden eyes half-lidded. Two Manticores pace the column perimeter. She speaks before the party is fully through the entrance: "I have waited long enough for someone interesting. Let us see if you qualify."
Opening Conditions
With the parchment (presented visibly): Arkteia rises, bows her great head slightly, and invokes the Right of the Riddled. No attacks until she has posed three riddles and received answers. The Manticores halt — tense, but still. This is the only way to access the full riddle challenge before violence begins.
Without the parchment: Roll initiative immediately. Arkteia may still use Riddle of Fate during combat, but there is no formal pause. She will not acknowledge the Right of the Riddled unless the parchment is produced mid-combat (costs an action to present; she will pause the following round only if she hasn't used her Multiattack yet).
Creatures
- 1× Arkteia — CR 10 (5,900 XP) · Boss
- 2× Manticore — CR 3 (700 XP ea.)
Ally (if Recruited)
- Atalanta — fights at party's side; targets Manticores first unless directed to use Silver Arrow on Arkteia
🗺 Terrain & Features
Summit oracle temple ruins — ~80×80 ft. open ring of columns, roofless, polished stone floor
- 12 marble columns (5 ft. diameter): Three-Quarters Cover while adjacent; can be toppled (DC 18 STR Athletics, action) — creatures in a 5×30 ft. line take 3d10 bludgeoning (DEX DC 14 half)
- Shattered altar stone (center, 15×10 ft.): Difficult terrain; Arkteia ignores this; provides Low Cover (half) if crouching behind the rubble
- Open sky above: Arkteia and Manticores fly freely; flying creatures cannot benefit from column cover
- Temple edge (all four sides): 50 ft. drop to the mountain slope — creatures pushed to the edge make DC 15 DEX save or go prone and hang from the ledge (another DC 14 Athletics to pull back up; falling = 5d6 damage)
- Oracle Basin (NE corner, cracked bronze dish): DC 14 INT (Arcana) check as an action to activate — glows gold, grants one creature within 10 ft. advantage on their next riddle answer; usable once per encounter
| Path | Condition | Outcome |
|---|---|---|
| ⚔ Combat Victory | Reduce Arkteia to 0 HP (Manticores flee at 50% HP if Arkteia is bloodied) | She goes dormant (stone-cracks form across her form). Routes open. Minor divine consequence. See Resolution. |
| 📜 Three Truths | Answer three riddles correctly (pre-combat via parchment, OR three correct answers accumulated during combat from Riddle of Fate uses) | Arkteia stands down fully. Reveals the ancient tomb beneath the altar. Offers a lasting boon. Best outcome. |
| 🧩 The Puzzle | Solve one of the three logic puzzles she offers at 50% HP as an alternative to continued combat | She agrees to relocate her domain off the trade routes. Neutral outcome — she is unharmed, not fully won over. |
Mechanics
- Opening (no parchment): Arkteia uses Paralyzing Roar immediately if available (Recharge 6 in Phase 1); otherwise opens with Riddle of Fate targeting the apparent group leader.
- Manticores open with Tail Spike volleys from range — they split targets across three party members if possible. They engage melee only if a target closes within 10 ft. of them.
- Arkteia Legendary Action priority: Claw Attack on most-injured target (Cost 1), Sandstorm Veil on clustered characters (Cost 2), Prophetic Judgment saved for a character about to land a devastating hit (Cost 3).
- Riddle of Fate: Arkteia uses this whenever recharged, targeting whoever looks most likely to succeed at a save (highest WIS-looking character first).
- Truth-Seeker (passive): If any PC told a lie in the last 24 hours, Arkteia knows it and will call it out by name at a dramatically appropriate moment — this is flavor but may unsettle the party effectively.
- Arkteia takes to the air (fly 60 ft.) and stays aloft for all subsequent turns. Grappling her while flying requires two successive contested STR checks (DC 15 each).
- Paralyzing Roar recharge improves to 5–6 while bloodied.
- At exactly 50% HP: Arkteia halts all attacks for one round and offers a puzzle. "You fight with more persistence than wisdom. Perhaps you are capable of this instead." — players may attempt the puzzle or decline and resume combat. She will not offer it again.
- Manticores shift to melee at Arkteia's 50% HP, attempting to grapple and drag characters toward the temple edge.
- If both Manticores are killed before Arkteia reaches 50% HP: she loses one Legendary Action use per round for the remainder of the fight (2/round instead of 3) — described as her losing focus to observe their defeat with narrowed eyes.
Mid-Combat (Riddle of Fate ability): Only the targeted creature may answer; other party members may help by making DC 12 INT (History) as a reaction to whisper a hint — success grants the target advantage on their answer attempt. Correct = regain 2d8 HP. Wrong or no answer = 7d8 (31 avg) psychic damage, INT DC 16 save for half.
DM Guidance: Choose one Easy, one Medium, and one Hard riddle for the formal challenge. Riddle #1 and #2 are good warm-ups. Allow 60 real-world seconds per riddle before calling a failure. If players approach creatively (a near-answer that shows understanding), accept it.
Riddle Bank (10 Riddles)
| # | Riddle (read aloud) | Answer | Difficulty |
|---|---|---|---|
| 1 | "The more of me you take, the more you leave behind. What am I?" | Footsteps | Easy |
| 2 | "I have cities but no houses, mountains but no trees, and water in which no fish swims. What am I?" | A Map | Easy |
| 3 | "I speak without a tongue. I hear without ears. I have no body, yet I come alive with the wind. What am I?" | An Echo | Easy |
| 4 | "When you have it, you wish to share it. When you share it, you no longer possess it. What am I?" | A Secret | Medium |
| 5 | "A king possesses me. A beggar needs me not. If you eat me, you shall die. What am I?" | Nothing | Medium |
| 6 | "Born in fire, shaped by mortal hands, cooled in the rivers of the earth — heroes wield me, and empires rise and fall by me. What am I?" | Bronze (accept: Iron, a Sword, a Weapon) | Medium |
| 7 | "I am stronger than the gods, yet I serve every mortal. I heal all wounds. I consume all things. I am the gift no one wants and the only certainty that waits for all. What am I?" | Time | Medium |
| 8 | "I have no beginning and no end, yet I hold all things in their place. The gods wear me. The very earth wears me. What am I?" | A Ring (accept: A Circle, a Chain) | Hard |
| 9 | "The one who makes me has no need of me. The one who desires me cannot use me. The one who uses me does not know it. What am I?" | A Tomb (accept: A Coffin, a Grave) | Hard |
| 10 | "I am always before you yet can never be seen. I am certain, yet I have never arrived. I am the one thing no hero has ever escaped, and no god has ever held. What am I?" | The Future (accept: Tomorrow, Fate, Death) | Hard |
Puzzle Options — Choose One
"Three stone vessels stand before you. The largest holds eight measures of sacred water — full to the brim. The second holds five. The third holds three. Both the second and third are empty. Divide the water so that two vessels each hold exactly four measures. You may pour only from vessel to vessel; not a single drop may be wasted. You have seven pours."
- Setup: Vessel A = 8 (full), Vessel B = 5 (empty), Vessel C = 3 (empty).
- Solution (7 pours exactly): A→B (3,5,0) · B→C (3,2,3) · C→A (6,2,0) · B→C (6,0,2) · A→B (1,5,2) · B→C (1,4,3) · C→A (4,4,0) ✓
- Accept: Any valid sequence arriving at 4,4,0 (or 4,0,4 or 0,4,4) in 7 or fewer pours.
- DM Tip: Draw three labeled boxes on a notepad. Let players physically track each pour state. The puzzle becomes immediately intuitive with a visual aid.
"A hero must carry four things across the River Styx: himself, a lion, a lamb, and a sheaf of grain. His boat holds only himself and one other. If left alone together: the lion devours the lamb; the lamb devours the grain. Bring all four to the far shore safely."
- Solution A (7 crossings): Hero+Lamb → return alone → Hero+Lion → return WITH Lamb → Hero+Grain → return alone → Hero+Lamb ✓
- Solution B (also valid): Hero+Grain → return alone → Hero+Lion → return WITH Grain → Hero+Lamb → return alone → Hero+Grain ✓
- DM Tip: Draw two shorelines on paper; provide four tokens (coins, torn paper scraps). The solution becomes apparent quickly once players can move pieces. If the group is stuck after 3 minutes, Atalanta (if present) may make DC 12 INT to offer a starting hint: "Take the lamb first."
"The Moirai weave all things according to a hidden pattern. I have carved their sequence into stone." [Arkteia traces the following into the altar's surface:] 1 · 1 · 2 · 3 · 5 · 8 · 13 · ___ "What number completes the chain?"
- Answer: 21 (each number equals the sum of the two before it — the Fibonacci sequence).
- Arkteia's flavor text on a correct answer: "The spiral of the nautilus shell. The branching of every olive tree. The petals of every flower offered to the gods. All things that grow follow this truth — even you, if you are patient."
- DM Tip: Write the sequence on paper and slide it across the table. Allow group discussion freely — this is a collaborative puzzle. If stuck after 2 minutes, Atalanta (if present) may roll DC 14 INT to recognize it and whisper: "Each number — add the two before it."
- Harder variant: Show only 1 · 1 · 2 · 3 · 5 · ___ (less context, harder to spot the pattern).
Resolution
- Nikias's Payment: 500 gp + permanent passage on his trireme to any port he sails (an ongoing favor, not a one-time trip).
- Arkteia's Hoard (combat or puzzle path — she doesn't share willingly): 1,200 gp in ancient gold coins; a Circlet of Blasting; one sealed clay tablet in Proto-Greek (DC 16 INT History to read — it's a cryptic prophecy about one of the PCs, DM writes this to fit the campaign).
- Three Truths Bonus: Blessing of the Sphinx (see above) for each PC; the clay tablet is still there but Arkteia hands it over freely — it names the PC and their role in a coming event.
- Ancient Tomb (Three Truths path only): Below the altar — a hero's burial chamber. Contents at DM's discretion: one +1 magic weapon wrapped in worn leather, one spell scroll (5th level or lower), and one piece of lore that hooks into the party's next adventure.
Creature Cards
Arkteia, the Sphinx
Large Monstrosity (Sphinx), Lawful Neutral · CR 10 (5,900 XP) — Boss
AC 16 (natural armor) | HP 145 (17d10+51) | Speed 40 ft., Fly 60 ft.
Saves: STR +10, CON +7, INT +9, WIS +8
Skills: Arcana +9, History +9, Perception +8, Religion +9
Immunities: Psychic; B/P/S (nonmagical) | Condition Immunities: Charmed, Frightened
Senses: Truesight 120 ft., Passive Perception 18 | Languages: All, Telepathy 120 ft.
Inscrutable. Immune to mind-reading and divination magic. WIS (Insight) checks against Arkteia have disadvantage.
Legendary Resistance (3/Day). When Arkteia fails a save, she may choose to succeed instead.
Riddle's Grace. A creature that correctly answers one of Arkteia's riddles has advantage on all saves vs. her abilities for 1 hour, and her attacks against that creature have disadvantage.
Truth-Seeker. Arkteia passively detects if any creature within 60 ft. has spoken a deliberate falsehood in the past 24 hours.
Multiattack. Two Claw attacks. If both hit the same target, she may make one Bite attack as a bonus action.
Claw. +10 to hit, reach 5 ft. Hit: 15 (2d8+6) slashing.
Bite. +10 to hit, reach 5 ft. Hit: 22 (3d10+6) piercing.
Riddle of Fate (Recharge 5–6). Arkteia speaks a riddle to one creature within 60 ft. that can hear. On that creature's next turn, it may answer. Correct: regain 2d8 HP. Wrong or no answer: 7d8 (31 avg) psychic; DC 16 INT save for half. Others may assist with DC 12 INT (History) as a reaction.
Paralyzing Roar (Recharge 6; Phase 2: Recharge 5–6). Each creature within 60 ft. makes DC 16 CON save or is Frightened and Stunned until end of its next turn. Creatures behind Three-Quarters Cover make this save with advantage.
Claw Attack (Cost 1). Make one Claw attack.
Sandstorm Veil (Cost 2). A 15-ft.-radius sphere of blinding grit appears centered on a point within 60 ft. Creatures in the area make DC 15 DEX save or are Blinded until end of their next turn.
Prophetic Judgment (Cost 3). One creature within 120 ft. makes DC 17 WIS save or is Paralyzed until end of Arkteia's next turn.
Manticore
Large Monstrosity, Lawful Evil · CR 3 (700 XP)
AC 14 (natural armor) | HP 68 (8d10+24) | Speed 30 ft., Fly 50 ft.
Senses: Darkvision 60 ft., Passive Perception 10
Tail Spike Supply. The manticore has 24 tail spikes. Regains all expended spikes after a Long Rest.
Multiattack. Three attacks: Bite + two Claws, or Bite + two Tail Spikes.
Bite. +5 to hit, reach 5 ft. Hit: 7 (1d8+3) piercing.
Claw. +5 to hit, reach 5 ft. Hit: 6 (1d6+3) slashing.
Tail Spike. +5 to hit, range 100/200 ft. Hit: 7 (1d8+3) piercing.
⚖️ Difficulty Scaling
As Written ★ — 6 Players, Average Level 6
- Baseline for this guide. Numbers, DCs, and win tracks assume six PCs at average level 6.
Library Standard — 6 Players, Average Level 8
- Raise key enemy HP ~+25% and damage +1 per attack die; social/skill DCs +1–2. Boss legendary actions as written or +1/round.
Easier
- APL 4–5: −1 enemy/wave; DCs −1; ally auto-recruits if approached peacefully.
Harder
- APL 7–8: use Library Standard (6×L8).
📋 Appendix — Cards
Full stat blocks for every creature, NPC, and character in this session. Clicking any tag-link in the document opens the relevant card as a popup.
Creature Cards
Siren
Medium Fey, Chaotic Neutral · CR 3 (700 XP)
AC 13 | HP 52 (8d8+16) | Speed 30 ft., Fly 50 ft., Swim 40 ft.
Saves: WIS +3, CHA +7 | Skills: Perception +3, Performance +9
Vulnerabilities: Fire | Senses: Darkvision 60 ft., Passive Perception 13
Languages: Common, Primordial
Alluring Song. Any creature within 60 ft. that can hear the Siren must succeed DC 15 WIS save at the start of each of its turns or be Charmed. While Charmed, the creature must use its movement to approach the nearest Siren and cannot willingly move away from it.
Multiattack. Two Talon attacks.
Talon. +5 to hit, reach 5 ft. Hit: 7 (1d6+4) slashing.
Captivating Dirge (Recharge 5–6). One creature within 120 ft. that can hear makes DC 15 WIS save or is Stunned until end of its next turn. On failure, a creature adjacent to a rail or drop edge falls from that edge.
Haunting Melody. When hit by an attack, the attacker makes DC 13 WIS save or has disadvantage on all attacks until end of its next turn.
Centaur
Large Monstrosity, Neutral Good · CR 2 (450 XP)
AC 12 | HP 45 (6d10+12) | Speed 50 ft.
Skills: Athletics +6, Perception +3, Survival +3
Charge. If the centaur moves ≥ 30 ft. straight toward a target and hits with Pike, target makes DC 14 STR save or is knocked prone.
Multiattack. One Pike and two Hooves.
Pike. +6 to hit, reach 10 ft. Hit: 9 (1d10+4) piercing.
Hooves. +6 to hit, reach 5 ft. Hit: 11 (2d6+4) bludgeoning.
Javelin. +6 to hit, range 30/120 ft. Hit: 7 (1d6+4) piercing.
Eurytion, Centaur Chieftain
Large Monstrosity, Lawful Neutral · CR 4 (1,100 XP)
AC 14 (natural armor) | HP 95 (10d10+40) | Speed 50 ft.
Saves: STR +7, CON +6 | Skills: Athletics +7, Intimidation +4, Perception +4, Survival +4
Charge. If Eurytion moves ≥ 30 ft. toward a target and hits with Pike, target makes DC 16 STR save or is knocked prone and pushed 10 ft.
Herd Commander. Centaurs within 60 ft. have +2 AC while Eurytion is conscious.
Multiattack. One Pike and two Hooves, or two Javelins.
Pike. +7 to hit, reach 10 ft. Hit: 11 (1d10+5) piercing.
Hooves. +7 to hit, reach 5 ft. Hit: 12 (2d6+5) bludgeoning.
Javelin. +7 to hit, range 30/120 ft. Hit: 8 (1d6+5) piercing.
War Shout (Recharge 5–6). All Centaurs within 60 ft. have advantage on attacks until start of Eurytion's next turn.
Trample. When a creature within 10 ft. moves away from Eurytion, he makes one Hooves attack against it.
Manticore
Large Monstrosity, Lawful Evil · CR 3 (700 XP)
AC 14 (natural armor) | HP 68 (8d10+24) | Speed 30 ft., Fly 50 ft.
Senses: Darkvision 60 ft., Passive Perception 10
Tail Spike Supply. The manticore has 24 tail spikes total.
Multiattack. Three attacks: Bite + two Claws, or Bite + two Tail Spikes.
Bite. +5 to hit, reach 5 ft. Hit: 7 (1d8+3) piercing.
Claw. +5 to hit, reach 5 ft. Hit: 6 (1d6+3) slashing.
Tail Spike. +5 to hit, range 100/200 ft. Hit: 7 (1d8+3) piercing.
Arkteia, the Sphinx
Large Monstrosity (Sphinx), Lawful Neutral · CR 10 (5,900 XP) — Boss
AC 16 (natural armor) | HP 145 (17d10+51) | Speed 40 ft., Fly 60 ft.
Saves: STR +10, CON +7, INT +9, WIS +8
Skills: Arcana +9, History +9, Perception +8, Religion +9
Immunities: Psychic; B/P/S (nonmagical) | Condition Immunities: Charmed, Frightened
Senses: Truesight 120 ft., Passive Perception 18 | Languages: All, Telepathy 120 ft.
Inscrutable. Immune to mind-reading and divination. WIS (Insight) checks against Arkteia have disadvantage.
Legendary Resistance (3/Day). When Arkteia fails a save, she may choose to succeed instead.
Riddle's Grace. A creature that answers one of Arkteia's riddles correctly has advantage on all saves vs. her abilities for 1 hour; her attacks against that creature have disadvantage.
Truth-Seeker. Passively detects deliberate lies spoken by any creature within 60 ft. in the past 24 hours.
Multiattack. Two Claw attacks. If both hit the same target, bonus action Bite.
Claw. +10 to hit, reach 5 ft. Hit: 15 (2d8+6) slashing.
Bite. +10 to hit, reach 5 ft. Hit: 22 (3d10+6) piercing.
Riddle of Fate (Recharge 5–6). Poses a riddle to one creature within 60 ft. that can hear. On that creature's next turn: correct answer = regain 2d8 HP; wrong/no answer = 7d8 (31 avg) psychic, DC 16 INT save for half.
Paralyzing Roar (Recharge 6; Ph. 2: 5–6). Each creature within 60 ft. makes DC 16 CON save or is Frightened and Stunned until end of its next turn. Three-Quarters Cover = advantage on save.
Claw Attack (Cost 1). One Claw attack.
Sandstorm Veil (Cost 2). 15-ft.-radius sphere within 60 ft. — DC 15 DEX save or Blinded until end of next turn.
Prophetic Judgment (Cost 3). One creature within 120 ft. — DC 17 WIS save or Paralyzed until end of Arkteia's next turn.
NPC / Ally Cards
Atalanta
Medium Humanoid (Human), Neutral Good · CR 6 (2,300 XP) — Recruitable Ally
AC 15 (leather armor) | HP 78 (12d8+24) | Speed 35 ft.
Saves: DEX +8, WIS +6 | Skills: Acrobatics +8, Athletics +5, Nature +5, Perception +9, Stealth +8, Survival +6
Languages: Common, Elvish, Sylvan
Favored of Artemis. Ignores difficult terrain in natural environments. No disadvantage on ranged attacks at long range. Advantage on WIS (Perception).
Hunter's Instinct. Always knows HP category (Healthy/Bloodied/Critical) of visible creatures.
Multiattack. Three attacks: two Shortbow + one Shortsword, or three Shortbow.
Shortbow. +8 to hit, range 80/320 ft. Hit: 8 (1d6+5) piercing.
Shortsword. +8 to hit, reach 5 ft. Hit: 8 (1d6+5) piercing.
Silver Arrow (1/day). +8 to hit, range 80/320 ft. Hit: 8 (1d6+5) piercing + 10 (3d6) radiant. Ignores piercing resistance. Target has disadvantage on attacks until start of Atalanta's next turn.
Hunter's Mark. Mark one creature. Atalanta's hits against it deal +3 (1d6) extra damage. Lasts until target dies or she marks another.
Nikias of Piraeus
Medium Humanoid (Human), Neutral Good — Quest Giver / NPC
Appearance: Late 60s, weathered skin, missing two fingers on his left hand (a scar he never explains). Grey-white hair, salt-stained captain's coat.
Motivation. Wants the sphinx stopped to re-open the trade routes he's sailed for forty years. Practical, not heroic.
Personality. Laconic. Doesn't embroider. Says what he means. Visibly rattled by the sphinx in ways he won't admit to.
Secret. Arkteia spared him — and he has no idea why. He's spent two years wondering if she was laughing at him. He will not discuss this unless directly pressed, and even then deflects.
Quote. "She didn't kill me. I still don't know why. Maybe she found me amusing. But she'll kill you — sure as Poseidon sinks ships — unless you're smarter than I was."
Pays 500 gp without haggling. If the party achieved Three Truths, he goes quiet for a moment, then says: "She spared me for the same reason, didn't she." It isn't a question. He doesn't wait for an answer.