Apocalypse Architect: A Tower Defense LitRPG

Chapter 61: Bounty Protocol System

Jax stared at the pile of rubble that used to be their dry-stacked stone wall. There was no defeat in his eyes, only the cold calculation of an engineer running a stress test.

His theory was confirmed: conventional materials were useless against the wasteland’s fauna. The Sandworms had smashed through the loose rocks like they were paper. To hold this sector, he needed the System’s architecture.

He didn’t have to wait long. The auto-turrets were cleaning up the stragglers of the current wave. It was a massacre, not a battle—basic Tier 1 Sandworms against military-grade hardware.

[System Alert: Tier 1 Sandworm eliminated.] [System Alert: Tier 1 Sandworm eliminated.] [Mission Complete.] [Rewards: Tier 1 Barricade x20. Unlocked: Tier 2 Barricade Upgrade Permission.]

Jax let out a breath he hadn’t realized he was holding. The tension in his shoulders uncoiled.

“Finally,” he muttered, dismissing the holographic overlay. “Actual Barricades, not just blueprints. That saves me the Stardust Stone I don’t have.”

That was the bottleneck. He still had no reliable source for Stardust Stone or Refined Iron. The trickle from daily missions was barely enough to maintain the status quo, let alone upgrade the fortress to survive the escalating threat levels. One failed mission, one missed objective, and the Penalty would set him back weeks.

He glanced at the ruined stone wall one last time, a plan forming in his mind. He ordered the team to rest. He, however, lay awake on the cold concrete floor of the safehouse, his mind racing with architectural layouts and the potential of Tier 2 fortifications.

The next “morning” was indistinguishable from the night. At 07:00, the sky was a bruised purple bruise, heavy with the threat of Black Rain. The gloom was oppressive.

Jax stood at the choke point of the canyon.

“Steep cliffs, granite composition,” he noted, running a hand along the natural rock face. “Hard enough to discourage digging. If the insectoids want in, they have to come through the gap.”

He paced the width of the pass. Twenty meters at the widest point. The bottleneck narrowed to less than ten.

He pulled up his inventory. Twenty Tier 1 Barricades sat in his spatial storage.

Using them all is a waste, he calculated. But a single line of defense is suicide.

He moved to the narrowest section—an eight-meter spread. “If I stagger the placement… create a kill box…”

He withdrew ten units. Each Barricade was five meters long, a heavy slab of reinforced, System-generated concrete. He placed them in an overlapping pattern, leaving a zig-zagging path exactly three meters wide. It was a classic tower defense strategy: never block the enemy completely. If you block them, they destroy the wall. If you leave a path, the AI—or their instinct—forces them to walk the gauntlet.

“Ten in reserve,” Jax murmured, closing the build menu. “Just in case.”

He checked his watch. The air smelled of ozone and wet earth. The Black Rain was coming, and with it, the monsters.

His thoughts drifted to the Spiked Dune Lord—that subterranean nightmare that had swallowed Captain Sterling’s squad. Will these walls stop a Tier 4 boss? Probably not. I need more firepower.

Night fell like a hammer.

The wind howled through the canyon, carrying the screech of distant horrors. Jax stood on the elevated platform of his base, flanked by his team.

[WARNING] [Tier 2 Rodent-Maw Creeper Swarm detected.] [Advisory: Load Energy Shards into Howitzer Turrets immediately.]

Jax checked his reserves. Forty Tier 1 Energy Shards. It sounded like a lot, but against a sustained siege, it was nothing. He remembered the Spiked Dune Lord shrugging off concentrated rifle fire. He needed every advantage.

[New Mission: Kill 50 Tier 2 Rodent-Maw Creepers.] [Reward: Unlock Bounty Protocol System.] [Failure Penalty: Builder Level -1.]

“Level down?” Jax’s eyes narrowed. The System was raising the stakes. But the reward… Bounty Protocol. That sounded like resources.

“Heads up!” Jax barked, his voice cutting through the wind. “Rodent-Maws inbound. Check your fire sectors.”

The team stiffened. They knew the score. Rodent-Maws weren’t mindless Sandworms. They were fast, vicious, and they could dig.

Kaleb racked the slide of his rifle, his face pale. “I’ve got one mag left, Boss. Make it count.”

Jax nodded grimly.

A minute later, the perimeter floodlights caught movement. Shaggy, hunched shapes scuttled at the edge of the light.

“Contact!” Kaleb shouted, shouldering his weapon. “One, two… five… shit, seventeen… I lost count! It’s a swarm!”

Jax ignored the count. His eyes were locked on the Barricades thirty meters out. That was the test.

Thwack.

The Sentry Tower engaged. A heavy crossbow bolt took the lead Creeper in the throat, pinning it to the dirt. The rest of the pack didn’t charge. They screeched and dove nose-first into the sand.

“They’re digging!” Silas yelled, gripping his spear. “They’re coming under the walls!”

Jax’s heart hammered against his ribs. This was the moment of truth. If the System Barricades didn’t have deep foundations, the base was defenseless.

He watched the mounds of earth snake forward like torpedoes in the water. They moved fast—until they hit the perimeter of the new construction.

The mounds stopped dead.

Ten seconds passed. Nothing moved.

“Did they… stop?” Kaleb whispered. “Or are they digging deeper?”

“Look!” Silas pointed.

At the far edge of the Barricade maze, the earth mounds shifted. They turned. Slowly, reluctantly, the subterranean tracks began to trace the open path Jax had left. They were forced to surface to navigate the turns.

“It works,” Jax breathed, a savage grin spreading across his face. “Pathing manipulation. Just like the game.”

He slammed two Energy Shards into the Howitzer Turret’s intake slot. The heavy machinery whirred to life, the black barrel traversing down into the kill box.

“Light them up.”

BOOM.

The ground erupted. The blast wave threw sand and insect ichor ten feet into the air. Four Rodent-Maws were blown out of their tunnels, their bodies broken and smoking. Before they could recover, the Sentry Tower turned them into pin-cushions.

[System: Tier 2 Rodent-Maw Creeper killed x1] [System: Tier 2 Rodent-Maw Creeper killed x1]

The strategy held. The remaining Creepers were forced into the choke point, slowed by the maze, and obliterated by the Howitzer. It was efficient. It was brutal.

[Mission Complete. Bounty Protocol System Unlocked.]

Jax didn’t waste a second. He pulled up the interface. A new tab pulsed with golden light.

He tapped it. A list of tiered bounties cascaded down: SSS, SS, S… all the way to F. Currently, only the F-Tier icon was illuminated.

He checked the time. 20:30. In his old life, this was prime gaming time. In the apocalypse, it was overtime.

He tapped the F-Tier icon.

[F-Tier Bounty Protocol] [Cost: 10 Tier 2 Cores] [Objective: Eliminate 100 Rodent-Maw Creepers.] [Time Limit: 60 Minutes.] [Reward: Refined Iron x100.] [Failure Penalty: -10 Bio-Score.]

Jax froze. “Ten Tier 2 Cores to start the mission? That’s highway robbery.”

He looked at his storage. He had fifteen Tier 2 Cores, saved painfully over the last week. This entry fee would wipe out two-thirds of his wealth.

But then he looked at the reward. 100 Refined Iron.

That was enough to upgrade the main gate. It was enough to build a Penetrator Ballista. It was power.

Jax gritted his teeth. “Scared money don’t make money.”

He hit [ACCEPT].

His inventory lightened instantly. Five Cores remained.

Down below, the gunfire had ceased. The team was slumping against the crates, exhausted.

“They’re retreating,” Kaleb sighed, wiping sweat and grime from his forehead. “We survived. I’ll take the first watch, Silas. You get some sleep.”

Silas chuckled, tossing a log onto the dying campfire. “No, you look like hell, kid. I’ll take first watch. Gareth, you’re off rotation tonight.”

“Hold up,” Jax called out, his voice cutting through their relief.

The team looked up, confused.

“Don’t get comfortable,” Jax said, racking a fresh magazine into his own weapon. “That was just the warm-up.”

“What?” Kaleb’s eyes widened. “Two waves in one night? That’s impossible.”

Jax didn’t explain. He looked out into the darkness, where the shadows were already beginning to shift again. He had paid for a war, and the System was about to deliver.

“We farm tonight,” Jax said coldly. “Get ready.”