The Stalker

This is a game script i wrote a couple years ago in Lua for Garry’s Mod, a mod which exposes the Source Engine (the engine used by Half Life 2, among other things) to Lua. I wrote the game around 2011. It took roughly 3 months to complete. In that time I had to program the game and also made a few maps for it using the Source SDK which took longer than expected to finish.

Being able to script a game using Lua bindings in a pre-existing engine is good fun since it’s relatively easy to get a working prototype up and running.

Here is a general description of the game:

A team of soldiers must hunt down a powerful, nearly invisible creature known as The Stalker. The Stalker has a number of abilities:

• Scream – A loud shriek that causes nearby soldiers to lose their hearing temporarily and disorients them. This attack uses 25% of your energy.

• Mind Flay – This attack invades the mind of the targeted player. They are heavily disoriented and take some damage from the attack. Perfect for picking off stragglers or confusing players who are very good at figuring out where you are. This attack uses 50% of your energy.

• Telekinesis – Control an object with your mind. You can choose the direction in which the object is thrown. A useful tool for distracting soldiers or causing damage with larger objects. This uses 75% of your energy.

• Blood Thirst – Your attacks absorb health for a short duration. Uses 100% of your energy.

• ESP – This ability is enabled/disabled by toggling your flashlight button as the stalker. When ESP is enabled, you can see where soldiers are through walls. However, while ESP is active, your energy will not replenish and your overall vision becomes darker.

The energy used by psychic attacks will slowly regenerate over time. In addition to having psychic abilities and being invisible, the Stalker is also very agile. It can jump to high areas, run faster than soldiers, and cling to walls. The Stalker’s health slowly drains over time but it regains health with each kill.

The soldiers have their own tools for hunting the Stalker. There are 4 different, equally balanced primary weapons to choose from, as well as 4 different secondary weapons and 4 utilities. Their flashlight runs off battery power and if your battery reaches 0% charge then there is a small delay before it starts recharging. The recharge rate for the battery is slower than its drain rate so you have to manage your flashlight use.

Primary Weapons:
• SG 552 – A highly accurate scoped rifle. Magazine holds 20 rounds.
• FN P90 – A SMG with a large magazine and a high rate of fire. Magazine holds 50 rounds.
• SPAS 12 – A powerful close range semi-automatic shotgun which can fire 6 rounds before reloading.
• FAMAS G2 – A 3-shot burst rifle. Magazine holds 30 rounds.

Secondary Items:
• Portable Sensor – A laser tripwire alarm which can be planted on any solid surface.
• USP Compact – A backup pistol with unlimited ammo.
• Seeker Drone – An autonomous drone which floats around and sounds an alarm if it detects the Stalker.
• Optic Range Scanner – A handheld scanner which augments your vision.

• Automedic System – An integrated morphine injector for your armor which heals you automatically when you are injured.
• Laser Module – A laser pointer attachment that fits any weapon.
• Extra Ammunition – Additional ammunition for your primary weapon.
• Dual Cell Battery – An improved battery which recharges faster and augments your flashlight.

Some screenshots:

Plenty of people have recorded videos of the game in action.

You can check out the code on assembla: