The illusionary wall shimmered, its magic settling into place. The mana crystal was now hidden from intruders—a crucial lifeline protected. But Oscar knew this was only the beginning.
He needed more than just a hidden resource.
He needed a dungeon.
Oscar focused on the Expand Dungeon command, and the system responded.
---
[Select Expansion Type:]
Natural Cavern (5 Mana per section) – Expands randomly, mimicking natural caves.
Structured Hallway (10 Mana per section) – Creates a designed corridor with walls.
Chamber Room (15 Mana per section) – A controlled open space for future traps or creatures.
---
Oscar didn't like randomness—strategy demanded control.
"Structured Hallway."
---
[Structured Hallway expansion in progress… 10 Mana consumed.]
Remaining Mana: 40/100
---
The cavern rumbled as the stone itself shifted, forming a narrow, controlled corridor leading from the core chamber.
Now, any intruders would be forced into a bottleneck. A perfect location for traps.
Oscar checked his dungeon map.
Core Room: His center of power, where he resided.
Mana Crystal Chamber (Hidden): Concealed behind an illusionary wall.
New Corridor: The first step toward an actual dungeon layout.
A single hallway wasn't enough.
If he wanted his dungeon to thrive, he needed to create something that wasn't just defensible—but deadly.
---
[Dungeon Expansion Options Available:]
Branching Paths (10 Mana per section) – Confuses invaders, forcing them to explore blindly.
Trap Room (15 Mana per section) – A dedicated room designed to hold deadly obstacles.
Monster Den (20 Mana per section) – A chamber meant for spawning additional creatures.
---
Oscar paused, calculating. His mana was low. He could afford one more expansion before needing to wait for regeneration.
He glanced at the goblin.
It was his only soldier—and a dungeon couldn't survive on just one.
"Monster Den."
---
[Monster Den created! 20 Mana consumed.]
Remaining Mana: 20/100
---
A cavernous space opened at the end of the corridor, its walls shifting unnaturally as an eerie mist settled in. The Monster Den was a dungeon's breeding ground, a place where creatures could spawn and grow.
Oscar opened the summon menu.
---
[Available Monster Summons:]
Slime (10 Mana) – Basic, weak, but can multiply.
Goblin (20 Mana) – Intelligent, capable of teamwork.
Rock Golem (50 Mana) – Durable, powerful, but expensive.
---
His mana reserves were too low to summon another goblin. The golem was out of the question.
Slimes were the only choice.
"Summon Slime."
---
[Slime summoned! 10 Mana consumed.]
Remaining Mana: 10/100
---
A small, translucent blue creature wriggled into existence, its form jiggling as it absorbed moisture from the air. Weak on its own—but it could multiply.
Oscar watched it carefully.
Every army needs numbers. The goblin could serve as a leader, and the slimes could become an expendable front line.
His dungeon was still small. Still weak.
But now, it had the foundation of a real defense.
And soon… adventurers would come.
And when they did?
They would never leave.
The Dungeon's First Prey
The silence of the underground chamber was broken by the faint gurgling of the newly summoned slime. The translucent creature wobbled in place, absorbing the dampness from the cavern air.
Oscar observed the creature through his Dungeon Sense. It was weak—too weak to fight anything on its own. But that was fine. Slimes had one advantage over other creatures.
Multiplication.
---
[Monster Information: Slime]
Type: Basic Dungeon Creature
Strength: Extremely low
Ability: Absorbs water to multiply over time
Combat Role: Swarm attacker
---
Oscar watched as the slime quivered slightly, then began splitting—one became two.
Good. My forces will grow on their own.
Even weak creatures could overwhelm stronger opponents if they had the numbers. It was a lesson Oscar had learned in his past life, commanding armies on the battlefield. The sheer weight of bodies in combat could turn the tide of war.
Still, his dungeon was far from ready.
He had:
One goblin (intelligent, armed with a bone dagger).
Two slimes (weak but multiplying).
A hidden mana crystal fueling his slow regeneration.
A single defensive corridor.
This was still a fledgling dungeon, barely a threat to any real adventurer.
And yet, fate had other plans.
---
[Warning! Unidentified presences detected near dungeon entrance.]
---
Oscar's awareness sharpened.
Intruders? Already?
He focused his Dungeon Sense outward, stretching it toward the entrance of his underground lair. Through the vibrations in the earth, he could detect movement—three distinct figures approaching.
Humans.
Oscar felt a flicker of cold amusement.
So, the first prey has arrived.
His menu updated, identifying the incoming threats.
---
[Adventurer Party Detected]
Name: Rookie Exploration Team
Members:
Ethan – Swordsman (Level 2) – Wields a short sword, lightly armored.
Mira – Healer (Level 1) – Basic healing magic, weak in direct combat.
Derrik – Scout (Level 2) – Light armor, skilled in traps and scouting.
Objective: Investigating newly formed dungeon.
---
Oscar immediately analyzed their strengths and weaknesses.
The swordsman, Ethan, was the primary fighter. His armor was weak, but against slimes and a lone goblin, he wouldn't struggle much.
The healer, Mira, was a problem. Even if her magic was weak, she could extend their survivability.
The scout, Derrik, posed a serious threat. His ability to detect traps and hidden passages might allow them to discover the mana crystal chamber.
Oscar's mind worked quickly. His dungeon wasn't strong enough for a prolonged battle. He needed to fight smart—ambush them, separate them, and kill them one by one.
"Goblin. Slimes. Prepare for battle."
The goblin grinned, tightening his grip on his bone dagger. The slimes quivered in anticipation, sensing the shift in the dungeon's energy.
The hunt was about to begin.
---
A Dungeon's First Kill
The adventurers stepped cautiously into the dungeon entrance.
The cavern walls were damp, the air thick with moisture. A faint, eerie glow illuminated the underground tunnel, but no obvious threats were in sight.
Ethan, the swordsman, stepped forward. "Stay close. This place feels strange."
Mira, the healer, clutched her staff. "Do you think there are monsters?"
Derrik, the scout, knelt, running his fingers along the ground. "Definitely a dungeon. Look here—these marks aren't natural. Someone—or something—shaped this passage."
The three ventured deeper, unaware that Oscar was watching their every move.
---
[Dungeon Ambush Plan Initiated]
Step 1: Lure them into the corridor.
The adventurers would have no choice but to follow the structured hallway, forcing them into a confined space.
Step 2: Block their retreat.
As soon as they entered, the goblin would quietly move behind them, cutting off their escape route.
Step 3: Overwhelm them.
Slimes would attack from the front, slowing them down.
The goblin would strike from behind, aiming for the weakest one first—the healer.
---
The adventurers stepped deeper into the corridor.
The moment they crossed the halfway point…
Oscar triggered the attack.
SLAP!
A slime launched itself from the ceiling, landing directly on Derrik's shoulder.
"AHH! What the—?!" The scout staggered back, trying to pull the jelly-like creature off his arm.
"MONSTERS!" Ethan raised his sword.
From the darkness, a second slime launched forward, latching onto Ethan's leg.
Then the goblin struck.
A blur of movement from behind—his dagger sliced toward Mira's exposed back.
"GAAH—!" The healer screamed, stumbling forward, blood staining her robe.
She was the weakest link. If she fell, the others would follow.
"Damn it! Mira!" Ethan swung his sword, forcing the goblin back, but the damage was done—Mira was already bleeding heavily.
Oscar watched with detached satisfaction. The battle was going as planned.
Derrik finally tore the slime off his arm, but his breathing was ragged. The slime's body had left behind an acidic residue, burning through his leather armor.
"Ethan, w-we need to retreat—!"
But when the scout turned toward the entrance—
The goblin was standing in their way.
Trapped.
Checkmate.
Oscar's cold amusement deepened.
This is what happens when you step into my domain.