Adventure Summary
The Goblins of Thornwall Fort is a medium-length assault and infiltration adventure designed for four 3rd-level characters. It can be completed in one 4–6 hour session.
Goblins seized Thornwall Fort while its garrison was campaigning elsewhere. When the exhausted soldiers returned, the goblins opened the gate, drew them into the courtyard, and slaughtered them. The king now needs capable adventurers to retake the fort before the goblins turn it into a permanent base for raids.
The war band numbers twenty-five, but roughly half are away raiding at any time. Thirteen currently occupy the fort. Careful characters can isolate them into several manageable groups. Reckless characters can alert the entire stronghold and face a much harder battle.
Expected Sequence
- Receive the king’s commission and learn what is known about the fort.
- Inspect the road where the garrison died and scout Thornwall.
- Choose a daytime assault, nighttime infiltration, disguise, or ambush.
- Neutralize the towers, courtyard, storehouse, and central keep.
- Defeat or drive off at least one returning raiding band.
- Secure the fort and recover its stolen wealth.
The Situation at Thornwall
Thornwall is a compact stone fort guarding the King’s Road. It has a ten-foot wall, two square towers, a central two-story keep, a low storehouse, and a single reinforced gate. The fort was built to hold forty soldiers but can be defended by far fewer.
What Happened
Three weeks ago, the garrison marched east with the royal army. A goblin war band led by Skab One-Ear found the nearly empty fort and overwhelmed the six servants and wounded soldiers left behind. The returning garrison saw familiar signal flags and entered without preparing for battle. Hidden goblin archers opened fire while Skab’s warriors barred the gate.
The dead soldiers now lie in a ravine half a mile from the fort. Skab dumped them there after stripping their armor and weapons. Crows gathering over the ravine make the site easy to find.
What the Goblins Want
Skab believes possession of a stone fort makes him a great warlord. His followers enjoy dry beds, stored food, and stolen treasure, but many are already bored. They raid farms and wagons for valuables, livestock, and anything polished enough to impress their leader.
Goblin Roster
| Location | Goblins | Current Activity |
|---|---|---|
| North tower | 1 goblin | Day: watching the north road. Night: dozing beside the brazier. |
| South tower | 1 goblin | Day: watching the gate and fields. Night: playing with a stolen spyglass. |
| Courtyard | 3 goblins | Arguing, cooking, and throwing knives at a painted shield. |
| Storehouse | 2 goblins | Sorting loot and drinking weak military ale. |
| Central keep | 5 goblins plus Skab | Two downstairs; Skab and three bodyguards upstairs. |
| Raiding countryside | 12 goblins | Three independent bands of four. |
Total: Twenty-four ordinary goblins and Skab One-Ear, for twenty-five goblins altogether.
Running the Fort
Day and Night
During daylight, both tower sentries actively scan the road, walls, and fields. At night, the goblins rely on the locked gate and their possession of the towers. The sentries are inattentive, the courtyard goblins move indoors when it grows cold, and most defenders sleep.
| Condition | Day | Night |
|---|---|---|
| Spotting a visible approach | Passive Perception 12 | Passive Perception 7 |
| Climbing an unguarded wall | Likely observed | DC 11 Dexterity (Stealth) after climbing |
| Defenders’ position | As listed in the roster | Courtyard goblins sleep in the storehouse; keep goblins are unarmored but can equip shields as an action |
| Party advantage | Clear visibility for ranged attacks | Characters can approach within 60 feet before making group Stealth checks |
The Alarm Track
Use three alert states. Move the fort up one state when a goblin escapes an encounter, a horn is sounded, the gate is forced loudly, or obvious combat continues for 3 rounds.
- Unaware. Each group remains in its listed location. Goblins investigate only sounds from the same building or courtyard.
- Suspicious. The courtyard goblins take cover, the keep’s downstairs guards bar the front door, and Skab sends one bodyguard to look from an upstairs window.
- Alarmed. The fort reacts in waves. Nearby goblins join after the delays below. Skab remains upstairs unless the keep catches fire or his followers flee.
| Noise Location | Immediate Defenders | Reinforcements |
|---|---|---|
| Tower or wall | Sentry in that area | Courtyard group arrives at the end of round 3 |
| Courtyard or gate | 3 courtyard goblins | 2 keep guards emerge at the end of round 3; storehouse group joins at the end of round 5 |
| Storehouse | 2 storehouse goblins | Courtyard group investigates at the end of round 3 |
| Keep ground floor | 2 keep guards | Skab and 3 bodyguards prepare upstairs but do not descend |
Morale
Ordinary goblins are brave only while they believe Skab is winning. A goblin flees or surrenders when it starts its turn with 5 hit points or fewer and no ally stands within 20 feet. When Skab falls, each remaining goblin must succeed on a DC 11 Wisdom saving throw or flee by the safest route.
Resting
The party can safely take one short rest after securing the storehouse or central keep. If they rest before controlling either building, roll once for a complication: on a 1 on a d6, a returning raiding band approaches the fort. This is warning, not an ambush; the characters hear crude singing several minutes before the band arrives.
The King’s Briefing
King Orren Vale offers the party 300 gp for proof that the fort has been cleared. He provides a rough plan of Thornwall, the key to a concealed drainage grate, and the following information:
- The fort has two towers, one gate, a central keep, and a storehouse.
- Scouts counted roughly twenty-five goblins, but never more than fourteen at once.
- Goblins raid during the day and return in small groups near dusk.
- The fort’s drainage passage emerges in thorn bushes north of the wall.
- The royal soldiers’ bodies have not been recovered.
Questions the Party May Ask
| Question | Answer |
|---|---|
| Can royal troops help? | The army is still campaigning. Ten militia will arrive the morning after the party signals that the fort is secure. |
| May we keep the loot? | They may keep coin, gems, goblin possessions, and unclaimed valuables. Goods marked with local family brands should be returned. |
| Must every goblin die? | No. Driving them away, capturing them, or forcing surrender fulfills the commission. |
| Can we damage the fort? | Minor damage is acceptable. Burning the keep or collapsing a tower reduces the reward by 100 gp. |
Approaching Thornwall
The Slaughtered Garrison
The King’s Road passes a shallow ravine half a mile west of the fort. Characters who investigate the circling crows find twenty-one stripped soldiers. Allow the party to bury them, mark the site, or press onward; this scene should establish the goblins’ cruelty without consuming much table time.
- DC 10 Wisdom (Medicine): The soldiers were killed by arrows from several directions, then finished at close range.
- DC 11 Intelligence (Investigation): A snapped gate bar lies among the bodies. The soldiers carried it out during a failed escape.
- DC 12 Wisdom (Survival): At least a dozen goblins left the fort this morning in three separate groups.
- Success on any check: The party finds a leather tube containing the commander’s sketch of the drainage channel. Characters using it have advantage on the check to enter through the grate.
Scouting the Fort
A character who spends 10 minutes observing from the tree line may attempt one check. Share useful facts on success; failure costs time but does not automatically alert the fort.
- DC 11 Wisdom (Perception): Count both tower sentries and note their poor nighttime discipline.
- DC 12 Wisdom (Survival): Find the north drainage outlet and identify fresh tracks from twelve absent goblins.
- DC 12 Intelligence (Investigation): Notice a broken section of southeast wall with easy handholds.
- DC 13 Charisma (Deception), using a captured goblin token or disguise: Convince a sentry that the party carries loot for Skab. The gate opens, but the courtyard goblins inspect them at close range.
Ways Inside
| Entrance | Method | Result |
|---|---|---|
| Main gate | DC 18 Strength with tools or 25 damage to the bar | Loud. Advances the fort to Alarmed. |
| Drainage grate | DC 12 Dexterity with thieves’ tools, or automatic with the king’s key | Enters the storehouse cellar unseen. |
| Southeast wall | DC 10 Strength (Athletics); DC 12 group Dexterity (Stealth) | Enters beside the storehouse. |
| Rope and grapnel | DC 12 Dexterity (Stealth) to place quietly | Choose an unoccupied wall section; a failed check makes the nearest sentry Suspicious. |
| Deception | DC 13 Charisma (Deception) | Gate opens. The courtyard goblins begin Suspicious but can be surprised by a quick attack. |
Fort Locations
The diagram shows relative positions rather than exact combat scale. Each wall is 10 feet high. Tower roofs are 20 feet above the courtyard, and the keep’s upper floor is 15 feet above ground level.
1. North Tower — The Sleepy Watch
1 GoblinHigh Ground
The sentry carries a signal horn. During the day it sounds the horn on its first turn unless prevented. At night it is sitting behind the battlement and must stand before it can see the ground outside.
- A character climbing from outside must succeed on a DC 12 Strength (Athletics) check.
- The interior ladder can be reached from the courtyard. Its hatch is unlocked.
- A creature behind the battlements has three-quarters cover against attacks from below.
- A thrown stone, animal noise, or minor illusion can draw the sentry to one side. A reasonable distraction succeeds with a DC 11 check using an appropriate ability.
Treasure: The spyglass here is cracked but usable and worth 15 gp.
2. South Tower — The Signal Post
1 GoblinAlarm Horn
The southern sentry watches the road by day. At night it experiments with a stolen brass spyglass, mostly looking through the wrong end. The tower contains a green goblin banner, a horn, 40 arrows, and a brazier prepared for a signal fire.
If the signal fire burns for 3 rounds, one raiding band sees it and returns in 20 minutes. Extinguishing it requires an action and access to the roof. Characters may instead light the fire after taking the fort to lure a raiding band into an ambush.
3. Courtyard — Knives and Kettle
3 GoblinsEncounter
Three goblins occupy the yard. They begin within 10 feet of the cookfire. If surprised, one spends its first turn grabbing a weapon. If prepared, they crouch behind overturned carts and fire shortbows.
- Cookfire: A creature can use an action to kick the pot, creating a 10-foot patch of scalding broth. A creature entering it for the first time must make a DC 11 Dexterity save, taking 1d6 fire damage on a failure. The patch then becomes harmless difficult terrain.
- Overturned carts: Provide half cover and can be pushed 10 feet with a DC 12 Strength check.
- Gate mechanism: Opening or closing the gate takes one action at the winch.
Clue: A chalkboard beside the keep door records the three raiding bands with crude symbols: a pig, a wheel, and a burning house. A character who reads Goblin learns the bands expect to return around sunset, midnight, and dawn.
4. Storehouse — Stolen Plenty
2 GoblinsLootSafe Rest
The two goblins are distracted. Unless the alarm is Suspicious or Alarmed, characters entering quietly surprise them on a successful DC 10 group Dexterity (Stealth) check. A sober character can also convince them to fetch Skab with a DC 12 Charisma (Deception) check, creating an opportunity to hide or set an ambush.
The drainage grate opens into a low cellar beneath the western shelves. Moving from the cellar into the storehouse requires a DC 10 Dexterity (Stealth) check because loose bottles cover the floor.
Treasure and supplies:
- Two potions of healing in a military medicine chest.
- Six days of rations for four characters.
- Twenty feet of rope, a climber’s kit, two flasks of oil, and a crowbar.
- Farm goods worth 90 gp, all marked with local names or brands. Returning them earns goodwill but no extra royal payment.
Once secured and barred from within, the storehouse is a safe place for one short rest.
5. Keep Ground Floor — The Old Barracks
2 GoblinsDefensible Room
Two goblins guard the barracks. If the fort is Unaware, one sleeps while the other repairs a shield. If Suspicious, both stand behind an overturned table that provides half cover. If Alarmed, they bar the door; breaking it requires a DC 15 Strength check or 15 damage.
The guards attempt to hold the room for 3 rounds. One then disengages and runs upstairs to warn Skab if no alarm has already been raised.
- Overturned table: Half cover; can be vaulted with 5 extra feet of movement.
- Staircase: Difficult terrain while a hostile creature stands at its top.
- Military gear: Two serviceable shields, four spears, and a suit of chain mail are scattered among damaged equipment.
6. Keep Upper Floor — Skab’s Throne Room
Skab One-Ear3 GoblinsFinal Encounter
Skab and three goblin bodyguards make their stand here. This is a hard but fair encounter for four rested 3rd-level characters. Skab begins behind the command table, while the bodyguards use benches for half cover.
Tactics
- Two bodyguards fire shortbows from cover. The third blocks the top of the stairs.
- Skab fights with his scimitar and uses Redirect Attack whenever possible.
- When only Skab and one bodyguard remain, Skab offers the treasure in exchange for escape.
- If reduced to 7 hit points or fewer, Skab attempts to flee through a narrow rear window onto the keep roof.
Player Options
- A character can tip the heavy command table with a DC 13 Strength check. Creatures behind it must succeed on a DC 12 Dexterity save or fall prone and lose its cover.
- The oil lamps can be extinguished with an action, leaving the room dimly lit by arrow slits.
- A character displaying proof that both tower sentries and at least five other goblins have fallen can demand surrender with a DC 13 Charisma (Intimidation or Persuasion) check. On success, one bodyguard surrenders immediately and Skab begins the encounter with disadvantage on his first attack.
Treasure: The command table holds 124 gp, 260 sp, a silver serving set worth 25 gp, three red garnets worth 10 gp each, and a polished brass astrolabe worth 40 gp. A locked drawer (DC 13 Dexterity with thieves’ tools) contains the fort commander’s signet ring and sealed orders proving how the garrison was deceived.
The Returning Raiders
The twelve absent goblins travel in three bands of four. They are not meant to attack simultaneously. The party should face at most one band before securing the fort and one afterward.
When a Band Appears
Choose the timing that best fits the party’s plan:
- Day assault: One band returns near sunset, after the party has cleared at least two locations.
- Night infiltration: One band approaches at midnight, carrying stolen chickens and singing loudly.
- Signal fire: A band arrives 20 minutes after seeing the south tower fire.
- Slow party: A band approaches if the characters spend more than two in-world hours resting or searching before taking the keep.
Running the Ambush
If the party controls the gate and at least one tower, they have a major advantage. The four raiders begin 120 feet away, clustered on the road and expecting a friendly welcome. Characters who prepared an ambush may make a group Dexterity (Stealth) check against passive Perception 9. On success, the goblins are surprised.
The band flees when two members fall. A captured goblin admits that the other bands will return separately and will abandon Thornwall when they see Skab’s banner removed.
Resolving the Other Eight Goblins
Avoid adding two repetitive battles. After Skab is defeated and one band is driven off, the remaining raiders discover the closed gate, royal banner, or bodies of their companions and scatter. If the players specifically want to capture them, resolve the hunt as a group challenge: the party needs three successes before two failures using DC 12 Survival, Stealth, Perception, Animal Handling, or a well-explained alternative. Success captures or drives off both bands. Failure lets four goblins escape into the countryside, but the fort is still cleared.
Conclusion and Rewards
Victory
The fort is cleared when Skab is defeated or expelled, the characters control the gate and keep, and at least one returning raiding band has been defeated, captured, or frightened away. Lighting a blue military lantern in the north tower signals the king’s scouts. Ten militia arrive the following morning to hold Thornwall.
Rewards
- Royal payment: 300 gp for clearing the fort.
- Recovered treasure: Coin and valuables worth 245 gp, plus the cracked spyglass worth 15 gp.
- Consumables: Two potions of healing.
- Royal favor: Returning the marked farm goods earns the party advantage on Charisma checks with local farmers and merchants for the next month.
- Commander’s signet: Returning it to the king earns each character a blue-enamel Thornwall badge. Once, its bearer can present it to receive modest lodging, supplies, or local militia assistance within the kingdom.
Partial Success
If Skab escapes but the fort is secured, the king pays the full reward, though Skab may return in a later adventure with a new band. If the keep or a tower is destroyed, reduce the payment by 100 gp. If the party retreats, the goblins become more alert but their numbers do not magically replenish; the characters may return after a long rest, though one absent band will have reinforced the fort.
Creature Statistics
These self-contained statistics keep the adventure ready to run. All ordinary members of the war band use the same goblin statistics.
Goblin
Small humanoid, typically neutral evil
Armor Class 15 (leather armor, shield)
Hit Points 7 (2d6)
Speed 30 ft.
Skills Stealth +6
Senses darkvision 60 ft., passive Perception 9
Languages Common, Goblin
Challenge 1/4 (50 XP)
Nimble Escape
The goblin can take the Disengage or Hide action as a bonus action on each of its turns.
Actions
Scimitar. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) slashing damage.
Shortbow. Ranged Weapon Attack: +4 to hit, range 80/320 ft., one target. Hit: 5 (1d6 + 2) piercing damage.
Skab One-Ear
Small humanoid, neutral evil
Armor Class 16 (chain shirt, shield)
Hit Points 27 (6d6 + 6)
Speed 30 ft.
Skills Intimidation +3, Stealth +6
Senses darkvision 60 ft., passive Perception 10
Languages Common, Goblin
Challenge 1 (200 XP)
Nimble Escape
Skab can take the Disengage or Hide action as a bonus action on each of his turns.
Actions
Multiattack. Skab makes two scimitar attacks.
Scimitar. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) slashing damage.
Shortbow. Ranged Weapon Attack: +4 to hit, range 80/320 ft., one target. Hit: 5 (1d6 + 2) piercing damage.
Reaction: Redirect Attack
When a creature Skab can see targets him with an attack, Skab chooses an allied goblin within 5 feet. The two swap places, and the chosen goblin becomes the target instead.
Scaling the Adventure
For Three 3rd-Level Characters
- Remove one goblin from the courtyard and one bodyguard from Skab’s room.
- Reduce Skab to 22 hit points.
- Have the returning raiding band flee after one goblin falls.
For Five or Six 3rd-Level Characters
- Add one goblin to the courtyard and one to the keep ground floor. These come from the absent raiders, so the total remains twenty-five.
- Give Skab 36 hit points.
- The returning band includes five goblins for five characters or six goblins for six characters.
For an Inexperienced Group
- Tell the players directly that a daytime frontal assault may unite the defenders.
- Have the king emphasize the drainage grate and the goblins’ poor night watch.
- Allow the party to find both healing potions before the first serious fight.
- Keep the final bodyguards behind cover rather than having them focus attacks on one character.
For a More Tactical Group
- The tower sentries use readied shortbow attacks against climbers.
- Suspicious defenders scatter simple hunting traps in the courtyard: DC 12 Perception to notice, DC 11 Dexterity save or fall prone.
- Skab extinguishes the upstairs lamps and uses Hide between shortbow attacks.
- Do not increase the number of goblins unless the party has five or more characters. Better positions create enough added difficulty.
GM Quick Reference
- Fort population: North tower 1; south tower 1; courtyard 3; storehouse 2; keep ground floor 2; upper floor Skab + 3. Twelve more are away in three bands of four.
- Alarm: Unaware → Suspicious → Alarmed. A horn, escaped defender, forced gate, or 3 rounds of loud combat advances the track. Reinforcements normally arrive after 3 rounds.
- Best entries: Drain grate opens automatically with the king’s key. Southeast wall requires DC 10 Athletics and DC 12 group Stealth. Deception at the gate requires DC 13.
- Key DCs: Scout 11–12; climb tower 12; distract sentry 11; bar keep door 15; tip command table 13; demand surrender 13.
- Final fight: Skab + 3 goblins. Benches grant half cover. Skab bargains when only one ally remains and flees at 7 hit points or fewer.
- Rewards: 300 gp royal payment; 245 gp in command-room valuables; cracked spyglass worth 15 gp; two potions of healing; royal favor for returned goods.