Undead Defense Tycoon 2 Weapons Lab and mercenary
Hologram guns that overheat, plus the $480k paratrooper.
Weapons Lab sits on the garage roof: hologram pads, laser kit, and the gate to the mercenary. This guide is how to complete that branch of the tycoon — unlock, overheat, merc levels — without treating Plasma Sword as a personality.
Unlock
Buy all normal floor guns you need and the entire garage building (cars optional). Lab appears with a sci-fi skin. If you rushed vehicles and skipped rifles, go back to getting started and the weapon tier list.
Lab is also a helipad prerequisite — vehicles. That is the #1 “missing pad” confusion.
Laser roster
| Weapon | Price | Combat role |
|---|---|---|
| Laser Blaster | $492k | Lab AR, medium heat |
| Laser Rifle | $565k | Scoped, ~5 shots, best sniper |
| Plasma Sword | $649k | Best melee |
| Energy Cannon | $773k | Burst shotgun, ~4 shots |
| Freonthrower | $1.35M | Slow + burn, Enraged |
| Photon Repeater | $2.2M | Ramp minigun, slow heat |
They recharge / overheat instead of mag-reloading. Hold-trigger farm scripts hate this — auto farm. Tap fire the Rifle; let Repeater spool.
Crate cousins: Railgun (1-shot heat), Zapper (chains). Not Lab pads — care packages.
Mercenary
Full walkthrough (video, levels, stairs): mercenary guide. Pad: left of the base, third floor, $480k, after Lab. The NPC parachutes in, 60s cooldown, one alive at a time (re-summon refreshes a different merc). Slow HP regen. Command: nearest zombie or defend owner.
| Level | Upgrade | Spawn cost | Guns | HP |
|---|---|---|---|---|
| 1 | $0 (pad $480k) | $2k | Pistol / Knife | 200 |
| 2 | $630k | $5k | SMG / Machete | 200 |
| 3 | $1.15M | $10k | AR / Tomahawk | 200 |
| 4 | $1.74M | $18k | AK / Katana | 275 |
| 5 | $2.38M | $30k | M60 / Plasma Sword | 350 |
Defend + Missile Truck + level 3+ is the lazy King/horde setup. Mercs can block truck doors. Stairs from the pad leak zombies — base defense.
It used to carry a medkit; that died in the helicopter update. You still need First Aid for King leech.
Spend advice
Lab guns are expensive. Photon Repeater is the pad minigun; M61 Vulcan is cheaper and already S-tier. Buy Lab building for heli access even if you delay Photon. Merc level 3 is the first one that feels like a teammate.
Use the cash planner before you click $2.38M because a green pad looked lonely. Upgrade path parks merc after M60 and mines, not before walls.
Scripts that touch this branch
Heli-fix scripts exist because Lab-gated helis used to eat propellers. That is a client hack, not a Box Games toggle — scripts. Play vanilla unless you accept safety risk.
Once Lab + merc + heli exist, you are in endgame: Devastator, King stacking, crate hunting. The rest is fashion and Hardcore.
Overheat in real fights
King leech does not wait for your Rifle to cool. Shoot five, drop to First Aid, shoot five. Photon Repeater wants a long unobstructed lane; it is wasted in merc stairs. Energy Cannon is for Mini blobs at the garage mouth, not for Alpha Tough skulls — zombie tiers. Freonthrower is the Enraged answer when you lack incendiary crates.
Merc micro
Nearest-zombie mode will chase a Mini into the forest and die to a Boomer. Defend mode will stand on your toes. Re-issue the command after each spawn. Level 1 mercs are decoys; do not pay $2k to watch a pistol tickle a Giant. The upgrade path waits for level 3 for a reason.
If the merc blocks the Missile Truck, get out, move him, get in. That is the whole tech. There is no “kick NPC” key on controls.
Frequently Asked Questions
Quick answers to the most common questions.
Do laser guns use ammo?
They overheat or recharge. Ammo+ gamepass does not help them.
Why did mercenary open my base?
The pad builds ground stairs. Set Defend and watch the hole, or kill what climbs.
Can I have two mercenaries?
No. Spawning another replaces/refreshes. One active NPC.
Is Plasma Sword worth $649k?
Only as a completionist melee. Guns and merc level 3 spend the same cash better.