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INTRUDER DESIGN DOCUMENT

CONTENTS

[1.0] Introduction
 [1.1] Acknowledgements
[2.0] The Vision
 [2.1] Description of Play
  [2.11] Space Combat Realities
 [2.2] Assumptions   [2.21] Jump Drives
  [2.22] Communications
  [2.23] Battlegrounds   [2.24] The Intruder
  [2.25] Detection
[3.0] Components
 [3.1] User Interface
 [3.2] Tactical Engine
 [3.3] Intruder/Fleet Design Module
 [3.4] Software Design Module
 [3.5] Strategic Engine
[4.0] Intruders
[5.0] The Fleet
[6.0] Interface
[7.0] Communications
[8.0] Combat
 [8.1] The Three Phases of Contact Prosecution
  [8.11] Contact Detection
   [8.11.1] Contact Signature Types
  [8.12] Contact Resolution
   [8.12.1] Contact Information Categories
    [8.12.1.1] Vector
    [8.12.1.2] Mass
    [8.12.1.3] Configuration
  [8.13] Contact Neutralization
[9.0] Offensive Systems
 [9.1] Kinetic Weapons
  [9.11] Kinetic Weapon Table
 [9.2] Missile Weapons
  [9.21] Nuclear Missiles
  [9.22] Kinetic Kill Missiles
  [9.23] Missile Bus Table
  [9.24] Missile Warhead Table
 [9.3] Energy Weapons
  [9.31] Coherent Light Weapons
[9.32] Charged Particle Weapons
  [9.33] Energy Weapons Table
[10.0] Defensive Systems
 [10.1] Point Defense
 [10.2] Interference Defense
 [10.3] Information Countermeasures
 [10.4] Defensive Systems Table
[11.0] Sensor Systems
 [11.1] Passive Sensors
 [11.2] Active Sensors
 [11.3] Weapon Directors
  [11.31] Bearing Only Launch
  [11.32] Beam Rider
  [11.33] Semi-active Radar Homing
 [11.4] Sensors Table
[12.0] Propulsion
 [12.1] Delta Vee
 [12.2] Fleet Thrust
 [12.3] Intruder Thrust
[13.0] Computer Systems
 [13.1] Software
 [13.2] Hardware
[14.0] Game Rules
 [14.1] Damage Calculation
  [14.11] Kinetic Weapons
  [14.12] Missile Weapons
  [14.13] Energy Weapons
 [14.2] Sensing Calculation
[15.0] Scenarios
[16.0] Glossary of Terms

[1.0] Introduction

Intruder is a game of information warfare and resource management set in the reaches of space. The basis of this game is an age-old strategy question. Assuming one side has one, extremely resilient and potent combat unit, and the other side has a fleet composed of small, relatively weak but numerous and varied combat units, how do you apply each side against the other to win?

The game may be played in a scenario-fashion with one player playing the Intruder and at least one other player commanding the ships of the Human Fleet. Additionally, a strategic layer to the game will allow for a massive on-line multi-player experience, with players commanding fleet movements around our galaxy, fleets and squadrons in system, and individual vessels. Optionally, an AI can be written to control the opposing side to allow for single-player games with a story line component.

Once the engine itself is built, it's fair to make the assumption that Fleet vs Fleet scenarios will take place. Another possible scenario would be Intruder vs Intruder, although the fun factor in that might be limited.

[1.1] Acknowledgements

This design has been rattling around inside my brain for some years, a product largely derived from my readings of Fred Saberhagen's Berserker series, Joe Haldeman's seminal Forever War and Larry Niven's Known Space. All the great ideas in this game come from their work; I accept responsibility for any of the ideas that really suck.

It was pointed out to me that Intruder is very much like Ogre in space (Ogre is a fun, engaging board game), a point I agree with now that I think about it. An acknowledgement to Steve Jackson of Steve Jackson Games is only right, and I apologize for not having seen the similarity sooner. The idea wellspring for the big unit vs. little units concept for me still originates with Saberhagen's Berserker series, however.

[2.0] The Vision

The story behind Intruder takes strategy and tactics to deep space. The Intruder, a menacing, powerful machine intelligence, is compelled to seek out and eradicate worlds that bear life. It is not particularly maneuverable, but has numerous weapons and is heavily armored. All it needs to do is orbit a life-bearing world, where it can use its weapons to scorch the planet surface, or, assuming it is heavily damaged, it can detonate itself and spread radioactive particles throughout the planetary atmosphere.

On the other side of the fence are the Colonial Fleets, a mixed group of warships left over from the Interregnum. Each colony system has its own fleet, and these ships, made up of gun cruisers, missile cruisers, railships, fighters, carriers and others must stop the Intruder from getting to their home planet. The Fleet must make several difficult tactical decisions that will dictate the way they attack the Intruder. If they make the wrong choices, their colony will pay the price.

A typical game of Intruder involves one player playing the alien menace he designs. He determines the type of hull, the amount of armor, power plant, propulsion, weapons and weapon placement, and operating programs that his Intruder will consist of. This design will be assigned a point value, and with the same number of points the Fleet player will purchase the ships that make up the defending forces.

The game really comes into its own with several players over a network. One player plays the Intruder, while numerous other players play the ships of the Fleet. When there are more ships than there are players, the extra ships will be assigned in groups to specific Fleet players.

There is also a grand strategic version of the game. A server can run a campaign where both a Fleet Admiral and the Intruder leader will determine production and logistics for a number of star systems. The Intruder's goal is to destroy all of the colonies in all of the star systems. The Fleet's goal is to reduce the effectiveness of the Intruders in the galaxy.

[2.1] Description of Play

Intruder will be utilizing principles of real-world physics in the game, so ships that create a vector must add an opposing vector to come to a "stop." This is a departure from most space games, where spacecraft have "throttles" that indicate the amount of absolute motion the craft will be travelling at.

Constant acceleration will cause a spacecraft to attain higher and higher velocities. Although travelling at very high speeds may seem cool, in combat you're nearly useless. A wise enemy will simply track your vector and arrange to have a missile or other object meet you further down your vector. At very high velocities, it won't matter if your ship was struck with a nuclear warhead or a prune. You'll disintegrate.

Much of the game will therefore be about maneuvering, conserving resources, and outguessing your opponent. Should the Fleet go after the weapons on the Intruder? But that won't slow the Intruder down, and all it has to do is orbit the colony to win, weaponless or not. What about attacking the propulsion systems? That's a good idea, but the problem lies in the leaving the Intruder's weapons free to carve up the Fleet. Additionally, once the Intruder's propulsion system is wiped out, the Fleet must make sure that the Intruder isn't headed straight for the colony, based on its last vector. Deflecting a mass as big as an Intruder is difficult. Railships and high-yield warheads from the missile cruisers can certainly do it, but do they have enough time?

A typical moment in the game would go something like this: a Fleet player, commanding a Railship, is watching his CTD. All of his passive sensors are cranked open; his ship is not maneuvering and is essentially running silent. After a minute or two, a contact flickers into existence. Almost immediately after, two more unidentified contacts in other locations appear. Which one is the Intruder?

A brief discussion between the Fleet players concludes with a decision to have the ELINT cruiser perform an active scan to begin prosecution of the contacts and reveal the location of the real Intruder. The ELINT cruiser will tight-beam the contact information to the other vessels.

The ELINT cruiser begins pinging and lights up. Two of the three contacts eventually resolve as decoy drones. The third contact returns information that tag it as the Intruder.

By this time, five more contacts appear, vectoring away from the Intruder. Active sensing reveals them to be missiles of some kind. The closest Fleet vessels acquire the Intruder as a target and plot firing solutions. Other Fleet vessels begin delta vee to position themselves for an attack.

Two missile cruisers and a frigate engage the Intruder by releasing ordnance, and one by one they're vaporized by counterattacks. The commander of the railship has already run the "align on target" program and has established a lock and firing solution. The railship is built around an enormously powerful weapon, but handles like a pig. The railship commander's pulse quickens as he sees the ELINT cruiser get vaporized by an Intruder weapon, and sees a contact hurtling towards his own vessel at a horrifying rate. It's a race between his ship aligning on target and the incoming contact…

[2.11] Space Combat Realities

Intruder is a major departure from your typical "space game" found on retail shelves. X-Wing, Wing Commander, Freespace, are all fine games, but they hardly attempt to be realistic simulations of combat in space. That's where this project comes in: when you kill your throttle, your vessel will continue on its last vector. Fuel becomes a consideration in the form of delta vee. Combat doesn't take place visually, most of the time. You'll be busy listening and watching for your enemy to give away their position while trying to stay undetected yourself. Information, the gathering of it for your side and denial of it to the enemy, will be the greatest key to success.

What this means is, if you're expecting to create another X-Wing where players are hot dogging it as fighter jockeys, this project isn't for you. "Twitch" will play little part in this game. We already have Quake, X-Wing, and the like available on the market. The goal here is to create a planner's game, as opposed to a reflex game. Not to say that there won't be plenty of moments in Intruder when your adrenal gland will be overworked. The method of playing will be vastly different, however, than what you may have experienced in space games to date.

The following is a series of "reality checks" that all of the developers should be aware of while working on the game, from artists to coders. Although the vision mandates a game that reflects the realities of space combat, please understand that some compromises will have to be made in the name of playability and game balance. This is, after all, a game we're developing.

Fleet ships are relatively easy to kill in Intruder. Standard military procedure would dictate that vessels are depressurized for combat so that explosive decompression won't disable a crew if hull integrity was compromised by an attack, but this only accounts for minor or incidental damage. Ships struck by weapons bearing a great deal of energy a fairly easy thing to deliver given the circumstances of space generally vaporize or are rendered useless in combat. The best defense is always remaining undetected. If the enemy can't see you, they can't attack you.

[2.2] Assumptions

This section has been added specifically to address many of the questions being asked on the mailing list. It'll be posted and updated on a regular basis on the Intruder site.

[2.21] Jump Drives

Jump drives allow a vessel to jump into a system given certain criteria [define].

[2.21.1] Jumps require a period of preparation that for purposes of tactical scenarios render them moot.

[2.21.2] Jumping into a system is *not* predictable, and the location of your arrival will be random inside of a fairly vast disc centered around the plane of the ecliptic.

[2.21.3] Jumping out of a system requires that you are at least [x distance] from a gravity well of [p intensity].

[2.21.4] Jump drives are effectively FTL. The time lapse between departure and arrival is exactly zero.

[2.21.5] Jump drives create an expanding sphere of handwavium particles. Out to a specific point, dictated by the density of those particles, objects within that sphere will be "jumped" to the destination. Destination points within a system are random and not predictable. This renders "point mining" impractical.

[2.21.6] Jumping *in* to a system reveals your location to the defending forces for a brief time.

[2.21.7] Intra-system Jumps do not exist.

[2.22] Communication

Communication in system is FTL. This effectively means communication is instantaneous, even in situations where light speed communications should take a few seconds to arrive.

[2.23] Battlegrounds

Fleets will start most scenarios in orbit around a planetary body.

[2.24] The Intruder

Intruders will be equipped with either an atrocity weapon or a seeding module in pursuit of their objectives.

[2.24.1] Atrocity weapons are Intruder modules that enable an Intruder to eradicate all life on a planet surface from orbit.

[2.24.2] Seeding modules enable an Intruder to build a repair/construction depot on a planet surface and extract mineral resources.

[2.24.3] Intruders have access to technology that is *different* from human tech, but not necessarily far more advanced in all cases. Gotta watch the handwavium and unobtainium levels here.

[2.25] Detection

Detection of Enemy Vessels is difficult.

[2.25.1] Fleet Vessels possess handwavium stealth technology that relies on a limited energy source. This is therefore an active stealth system.

[2.25.2] Intruders also possess handwavium stealth technology, but it does not rely on a limited energy source. This is a passive stealth system, and is slightly less effective than the Fleet's active stealth.

[2.25.3] Ships and Intruders that use their reaction drives will show up on sensors automatically. This is also known as torching.

[2.25.4] Ships and Intruders that use active sensors will show up on sensors automatically. This is also known as lighting up.

[3.0] Components

The first four components listed here require development before we start on further components.

[3.1] User Interface

The UI for Intruder is keyboard and mouse driven. Contrary to design practices for most space games, Intruder postulates that most navigation and piloting functions are executed with precision by on-board computer systems (imagine that!)

The current vision for the UI is a departure from the usual "HUD on the canopy" fighter-combat paradigm. Instead, partly as a nod to movies like Star Wars and Star Trek: Wrath of Khan but mostly because it makes sense, we're assuming that combat takes place entirely by instrumentation and not by the pilot's visual acuity. This means that the most important display on the screen will be the Central Tactical Display.

The CTD is a 3-D representation on the screen of a globe of space that surrounds the player's vessel. The extent of the globe is dictated by the range of the vessel's sensors, and adjusts accordingly. Detected contacts within sensor range are tagged, and selecting a specific contact reveals resolved information.

Beside or surrounding the CTD are smaller windows that show optic or other sensing information, delta vee status, systems status, and software operations.

[3.2] Tactical Engine

The core of the tactical engine is divided into several modules.

[3.21] The active physics engine is responsible for holding the remainder of the game to a set of rules describing how mass and energy act and interact in the game context.

[3.22] The battleground engine describes the solar system in which a given scenario is played out.

[3.23] The scenario engine is responsible for setting the terms and conditions of the current battle. Victory conditions for the Intruder and the Fleet(s) involved, any special factors such as time limits are handled in this module.

[3.24] The player engine handles all player interaction with the game via the UI and the AI modules. "Player" in this context refers to any entity engaged in a scenario, whether it be a human sitting at the keyboard, a human at another computer taking part via a network or the Internet, or an AI controlled by the computer.

[3.3] Intruder/Fleet Design Module

The Intruder/Fleet design module will be specified in greater detail in the game specification document.

[3.31] The Intruder

The Intruder will be designed principally by a human player if one is available to play the Intruder. It will be selected randomly from preconfigured designs in singleplayer games where the player elects to control the Fleet.

[3.32] The Fleet

The Fleet(s) will be partially assigned to the human player(s) controlling them with components selected from preconfigured ship lists. A certain number of ships are assigned arbitrarily, perhaps with influence from the scenario engine. The remainer are selected by the player, within constraints based on the Intruder's strength and any senario constraints that apply.

[3.33] Preconfigured Ship Designs

Both the Fleets and the Intruder will be pre-defined for selection within the game. These pre-defined ship designs will be created during the game design phase using a genetic algorithm and a rough combat simulation program. The genetic algorithm will begin with roughed out ship design specifications and run these ship designs through one or more simulations to determine the relative fitness of the designs. The designs will then be "bred" (genetically recombined) into new generations which are subsequently tested and refined.

The process will vary somewhat between the Intruder and the Fleets. Intruder vessels are generalized, as their design intent was aimed at (hopefully) making them capable of handling anything they come across in their interstellar voyages. The Fleets, on the other hand, are specifically designed for combat with other human-built Fleet craft. As such, the Intruder fitness algorithms will be general fitness tests while Fleet designs will be tested against other Fleet designs in combat simulations.

[3.4] Software Design Module

[3.5] Strategic Engine

Although Intruder is inherently a tactical game, the game model lends itself well to the application of a "Strategic Layer" that allows for a campaign game with a massive number of players. The ultimate goal of the game for the Fleet is to find the Intruder staging world, destroy the repair depot, and hunt down all of the Intruders in the local star cluster. All the Intruder has to do is find and destroy the home planet of the Human Fleet, namely Earth.

Maneuver and position within the strategic game is facilitated with the use of Jump Lines, links between star systems that can be used by Jump Ferries and Intruders and the limited number of vessels (in the case of the former) that can travel with them. This will dictate positions of importance within the campaign, as certain star systems must be captured to allow for a jumping-off point to other systems.

The central screen for the strategic component will be the System Map, where the various star systems and their production values are displayed, along with a web of Jump Lines showing which system can be used as a jump-off point for the next.

Each System is also rated for Resources and Recruitment. The first value indicates the number of Resource Points the System generates each "turn." The second value indicates the number of crew produced per time unit for use in the Fleet. Both resources and crew are necessary to build and man new Fleet ships. The Intruder has no such limitation.

But on the same note, the Intruders cannot build more of their kind, and are instead given a reinforcement schedule. All reinforcements arrive at the Intruder staging world, where damaged Intruders can be repaired and rearmed.

[4.0] Intruders

Intruders are made up of nine key components:

[4.1] A Hull

[4.2] Power Plant

[4.3] A Propulsion System

[4.4] Protection

[4.5] Weapons

[4.6] Sensors

[4.7] Computer System

[4.8] Software

[4.9] Support Systems

[5.0] The Fleet

Human Fleets (or just 'Fleets') are made up of ships. Each ship in the Fleet can be broken down further, along lines similar to the Intruder as specified in section [4.0], but with the notable addition of a Crew section for manned vessels. One Fleet configuration might look like this, in broad strokes.

Satellite Stations [SA]

Drones [DR]

Fighters [SF]

Assault Boats [AB]

Frigates [FF]

Railships [CR]

Missile Cruisers [CM]

Gun Cruisers [CA]

Tankers [AO]

Command Cruisers [CC]

Elint Cruisers [CE]

Carriers [CV]

Jump Ferries [FJ]

[6.0] Interface

The User Interface (UI) in Intruder consists of a display made up of several components. These components, when used together, provide the user with a realm of information that describe the tactical situation around him.

[6.1] There are four basic elements to the UI: the Computer Processing Display, the Communications Window, the Central Tactical Display, and the Constant Data Display.

[6.11] Computer Processing Display: This lists the programs that are available to the player on his ship. The programs that are running are highlighted. The section should be able to display selections at the same time, and is scrollable.

[6.12] Communications Window: This is where all communications takes place between Fleet vessels (and potentially multiple Intruders). An amber arrow indicates the beginning of a new transmission/reception. For identity of the transmitter, the ship name should appear in square brackets just after the amber arrow. This Window should be scrollable with a history buffer, and should also implement the much-requested Quake-style console command interface.

[6.13] Central Tactical Display: This display shows the space surrounding the player's vessel, with a backdrop grid used for distance reference. Note that the grid must show all three axes, and as such should probably be made up of three planes crossed and rotating.

Each grid square should scale according to the scan range set for each sensor. This can be done simply by changing the distance value of each square. The minimum grid setting should be 1k per square. Magnitude increments of ten should work sufficiently - 1k, 10k, 100k, 1,000k, 10,000k and 100,000k should cover most eventualities.

The size of the grid should adjust according to sensor values. A passive sensor that's rated for 40,000k should be 4 squares by 4 squares, for example.

Sensor readings should indicate type of ship, friend or foe with a contact ID. A vector arrow should be tagged onto the contact, showing direction and velocity, and a drop or increase in velocity (is he accelerating or decelerating?).

The vector arrow will be white if the vessel is not changing velocity, red if it is receding, and blue if it is approaching. The velocity of the vessel relative to the player's vessel can be determined by a lock.

[6.14] Constant Data Display: This display is configurable by the user. It has three slots, and all slots are assignable. Each datum category (such as RV) can be placed in the CDD at the player's whim. Some datum categories are:

RV: Relative Velocity (relative velocity in km/s)

DTL: Distance To Lock (in km, and in seconds)

THR: Current Thrust Setting

XYZ: Position on axes (0,0,0 is predetermined 'nav beacon')

DTI: Distance To Impact (last fired missile weapon, in km and in seconds)

KTI: Kinetic weapon Time to Impact (time to hit lock with currently selected KW in seconds)

There should also be room for three user definable entries: the Fleet/Intruder logo of their choosing, the class and name of ship they're controlling, and the rank and name of the player. Rank is earned, and is derived from a player config file. The name of the ship has a default, or may be named by the Fleet commander or the player (server setting). The name of the player is set by the player.

Point for Discussion: Player configurations could be assigned a player ID, enabling the system to cope with duplicate player names on the same system or across networks in distributed multiplayer play. This intruduces the potential for confusion, but might be necessary in a distributed network environment where name collision detection is rendered all but impossible.

[7.0] Communications

The Fleet Admiral can assign up to 9 "channels." Each channel is bound to specific ships in the Fleet. For example:

Channel 1: Railships, Jump Ferries

Channel 2: Fighter channel

Channel 3: Assault Boat channel

Channel 9: Flagship Defense ships (two Gun Cruisers and two Fighters)

Channel 0 is reserved for the "general freak" or all-ship frequency.

This reduces clutter on a player's comm screen and allows for orders to only go to specific ships, thereby reducing confusion as well.

Point for Discussion: Perhaps include software options that allow the Intruder/Fleet to "decrypt" enemy transmissions and get partial strings of communications going back and forth?

[8.0] Combat

[8.1] The Three Phases of Contact Prosecution

There are three phases in the military methodology known as Contact Prosecution. The phases are, in order, detection of the contact, resolution of the contact, and destruction or neutralization of the contact.

[8.11] Contact Detection

The first phase in Contact Prosecution, specifically detecting a possibly hostile contact with passive or active sensors. Once a contact has been detected, it is assigned a Contact ID by the shipboard tactical computer. A Contact ID takes the form of {Type|Serial}, where Type is a letter code for various contact signature types and Serial is a three-digit number starting from 001.

During this phase, all you know about the contact is that your sensors think there is something there.

[8.11.1] Contact Signature Types

[8.12] Contact Resolution

The second phase in Contact Prosecution is Resolution, where a sensing vessel collects more information through sensor packages. There are several information categories to be collected on an unresolved contact.

[8.12.1] Contact Information Categories

[8.12.1.1] Vector (direction, relative speed)

[8.12.1.2] Mass

[8.12.1.3] Configuration

[8.13] Contact Neutralization

This final phase of Contact Prosecution involves the destruction or neutralization of a contact that has been determined to be hostile through the deployment of weapons.

[9.0] Offensive Systems

There are three general types of offensive systems: Kinetic, Missiles, and energy weapons.

[9.1] Kinetic Weapons

Kinetic weapons are semi-guided ordnance that deliver damage to a target by transferring energy through some physical medium, such as a slug. Slugs are typically launched at a velocity of 5 to 40 Km/sec.

[9.11] Kinetic Weapon Table

Kinetic Weapon Mass of Slug Muzzle Velocity ROF (rnds/min) Damage per Round Heat Signature

50mm Autocannon 0.25 kilos 12500 m/s 4000 20 0.5

125mm Shrapbore 9 kilos 6200 m/s 30 173 0.9

360mm Gun 30 kilos 5500 m/s 16 454 0.8

450mm Gun 42 kilos 8000 m/s 6 1344 1.2

Spinal Railgun Mk I 120 kilos 40000 m/s 2 96000 1.3

[9.2] Missile Weapons

Missile weapons are fully-guided ordnance that deliver damage to a target by detonating a warhead of some type to either directly transfer energy to the target or to power a weapon in that warhead. There are two broad types of missile: Nuclear and Kinetic Kill.

[9.21] Nuclear Missiles

Nuclear missiles deliver either a blast of explosive energy with the aim to vaporize contacts (60 megatons will vaporize steel at 500 meters) or detonate and power a single-shot directed weapon such as an x-ray laser at fairly short range (say 5 km).

[9.22] Kinetic Kill Missiles

Kinetic Kill missiles fragment themselves to behave as a clump of kinetic-energy carrying metal, akin to a shotgun blast. These are much harder to defeat with point defense, as there are many targets to deal with instead of just one. A nuclear missile, however, can defeat this sort of attack as the area effect will vaporize the clump.

[9.23] Missile Bus Table

Missile Bus Mass of Missile Burn Time Acceleration Heat Signature

Valkyrie Mk III 90 kilos 12 seconds 30.0 gees 0.5 (nontorching)

Valkyrie Mk IV 95 kilos 20 seconds 27.0 gees 0.5 (nontorching)

Odin Mk I 160 kilos 28 seconds 36.0 gees 0.5 (nontorching)

[9.24] Missile Warhead Table

Warhead Damage Method Damage Delivered

Warflail Aleph Kinetic Cloud

Forge Aleph Kinetic Cloud

Hephaestus Nuclear Explosion

Thor Nuclear Pumped Weapon

[9.3] Energy Weapons

There are two families of energy weapons: coherent light weapons and charged particle weapons. Both of these families have similarities. The first being that, for all intents and purposes, at distances where they can put a sufficient energy density onto the target, they effectively don't "miss" outright. They just fail to stay on the same centimeter of the target for the fraction of a thousandth of a second for it to penetrate.

[9.31] Coherent Light Weapons

Most lasers will be on the fringe of the high UV/soft X-rays, so will be invisible to the naked eye. If the firing ship has a targeting solution, either type of beam weapon will hit nearly automatically. This also impacts missiles and slug throwers; they can see those coming, and they can't dodge lasers any more than your ship can.

Rule of thumb for effective laser ranges is: I=(P/[L/D]^2)/R^2

Where I = intensity in Joules per square cm. P = Discharge in Joules L = Wavelength of laser in cm. D = Focusing element diameter in cm. R = Range in cm.

A 900 megajoule laser will, for example, have an effective range of 1000 km or so.

[9.32] Charged Particle Weapons

Charged particle weapons are more subject to diffusion over range, and for game purposes are effective out to 400km. At close ranges, say out to 50km, they're devestating.

[9.33] Energy Weapons Table

[10.0] Defensive Systems

There are three general types of defensive systems: point defense, interference, and information countermeasures.

[10.1] Point Defense

Point Defense weapons are relatively short-ranged but very precise weapon systems designed for the sole mission of either knocking an incoming weapon off its vector or vaporizing it entirely. A good example of this is the wet Navy's Phalanx system, a high ROF gun that uses lidar to track an incoming missile and adjusting a steady stream of lead to knock the missile down.

Point Defense weapons can cause damage to enemy vessels at close range, but the are relatively weak compared to weapons that have missions as offensive systems.

[10.2] Interference Defense

Interference defenses involve interposing a layer of mass or energy between the incoming attack and the vessel. Examples of this include chaffcasters, which throw up a wide sheet of granulated matter in an attempt to block energy attacks; powerful electromagnetic fields that first infuse a missile with a negative charge then repel the missile with a positive field; and an ablative defense offered by armour, which can often just be mass that needs to be vaporized before the internal critical systems of a vessel can be affected.

[10.3] Information Countermeasures

The most potent form of defense, following the rationale of "if they can't target/see you, they can't attack you."

Information Countermeasures include Decoys, which offer a signature similar to your own vessel in a passive state; ECM, which can be used to confuse fully guided tracking systems; and ECCM used to counter ECM.

[10.4] Defensive Systems Table

[11.0] Sensor Systems

Sensor suites are the eyes and ears of any spacecraft, Intruders included. Type is either Passive or Active active sensors must "ping" to seek contacts, and offer much more detailed and accurate information than passive sensors do, but they also instantly reveal the location of the "pinging" vessel. Range indicates the maximum effective range of the sensor. Resolution indicates the quality of information from the sensor (1.0 is perfect).

[11.1] Passive Sensors

[11.2] Active Sensors

[11.3] Weapon Directors

[11.31] Bearing Only Launch

This weapon guidance system is given a vector and burn time before launch. When launched, it travels on that vector at maximum acceleration until the burn time is reached, whereupon the homing system switches on, the missile selects a target, and travels at maximum burn towards the target.

[11.32] Beam Rider

The missile is controlled by the launching vessel by pointing a radar|lidar at the target that the missile follows. The missile travels along the vector at maximum burn until it reaches the target. If the beam is interrupted, the missile self-destructs.

[11.33] Semi-active Radar Homing

The missile is given a target by the launching vessel, which is illuminated by the missile's own active guidance system after launch. The missile corrects its course during approach as necessary.

[11.4] Sensors Table

Sensor Package Active/Passive Information Attenuation Effectiveness

Radar Active Bearing, Range 0.75

EMI Passive Bearing 0.3

IR Passive Bearing 0.55

MAD Passive Bearing, Range 0.4

Lidar Active Bearing, Range 0.8

Optical Passive Bearing 0.1

[12.0] Propulsion

The basic assumption for propulsion is that Fleet vessels utilize a fusion-powered reaction drive. Intruders may have both a reaction drive and an inertialess drive; the former will obviously be far more common and affordable.

[12.1] Delta Vee

Delta Vee will be limited for both Intruders and Fleet vessels.

[12.2] Fleet Thrust

Fleet vessels can operate at up to 12 gees. The limitation here is based on human endurance. Conditioned humans can handle up to 12 gees for a few seconds and 6 gees for a few minutes.

[12.3] Intruder Thrust

Intruders can operate at up to 25 gees thrust. This is an arbitrary limitation.

[13.0] Computer Systems

[13.1] Software

Software modules are a critical component of gameplay in Intruder. Although every ship and every system on every ship can be operated manually, players who prepare modules for their ships will be able to perform tasks much more efficiently. This is because the modules allow for multiple functions to be executed at the stroke of a key, and the computer handles all of the controls to fulfill the function requirements.

There are three types of software modules: Navigation, Combat and Support. Navigation modules execute ship maneuvers, combat modules execute offensive and defensive system orders, and support modules execute all other orders that do not fall into the first two categories.

There are three primary steps to designing a module:

1. Select Navigation, Combat or Support

2. Add Subroutines and Define Affected Components

3. Compile Module

Step 2 is the most involved, but is still relatively simple. The player selects the subroutines he wishes to implement in his module, specifies the affected components (such as which hardpoints to affect with the order) and places the subroutines in the order of execution he desires.

Navigation Subroutines

All Navigation Subroutines with the term Vector will have a user changeable entry for the Thrust value.

· Set Vector Stationary relative to Closest Enemy/Friend

· Set Vector Stationary relative to Furthest Enemy/Friend

· Set Vector Stationary relative to Most Powerful Enemy/Friend

· Set Vector Stationary relative to Least Powerful Enemy/Friend

· Set Vector Stationary relative to Tagged Enemy/Friend

· Set Vector Stationary relative to Planet

· Set Vector Stationary relative to Closest Gravity Well

· Set Vector Stationary relative to Strongest Gravity Well

· Set Vector to Close with Closest Enemy/Friend

· Set Vector to Close with Furthest Enemy/Friend

· Set Vector to Close with Most Powerful Enemy/Friend

· Set Vector to Close with Least Powerful Enemy/Friend

· Set Vector to Close with Tagged Enemy/Friend

· Set Vector to Close with Planet

· Set Vector to Close with Closest Gravity Well

· Set Vector to Close with Strongest Gravity Well

· Set Vector to Retreat from Closest Enemy/Friend

· Set Vector to Retreat from Furthest Enemy/Friend

· Set Vector to Retreat from Most Powerful Enemy/Friend

· Set Vector to Retreat from Least Powerful Enemy/Friend

· Set Vector to Retreat from Tagged Enemy/Friend

· Set Vector to Retreat from Planet

· Set Vector to Retreat from Closest Gravity Well

· Set Vector to Retreat from Strongest Gravity Well

· Set Vector to Jink

· Set Vector to Zig Zag

· Engage Jump Field (Jump Ferries and Intruders only)

Combat Subroutines

· Target Closest Enemy

· Target Furthest Enemy

· Target Tagged Enemy

· Target Most Powerful Enemy

· Target Least Powerful Enemy

· Target Nearest Closing Enemy

· Target Nearest Retreating Enemy

· Target Most Powerful Weapon System

· Target Least Powerful Weapon System

· Target Propulsion

· Target Hull

· Fire Weapons at Current Status

· Fire Weapons at Full Intensity (Beam/Rail only)

· Fire Weapons at Three-Quarters Intensity (Beam/Rail only)

· Fire Weapons at Half Intensity (Beam/Rail only)

· Fire Weapons at One-Quarter Intensity (Beam/Rail only)

· Fire Weapons Pulsed (Specify Pulse Intervals)

· Cease Fire Weapons

· Cease Fire Drained Weapons

· Cease Fire Energy Weapons

· Cease Fire Kinetic Weapons

· Cease Fire Missile Weapons

Support Subroutines

· Ping with Active Sensor (Specify number of Pings)

· Switch Off All Pings

· Activate Security Procedures

· Deactivate Security Procedures

· Activate ECM

· Deactivate ECM

· Activate ECCM

· Deactivate ECCM

· Place <specific gauge> on HUD position X

· Transmit orders <file.txt> on channel X

[13.2] Hardware

[14.0] Game Rules

Game Rules focuses on the methods of incident resolution, specifically Damage Calculation (how much damage does an attack inflict) and Sensing Calculation (how to determine if a vessel senses a contact).

[14.1] Damage Calculation

Damage Calculations are based on the energy delivered to a target.

KE = 0.5(Mv)

Where M = momentum, which is mv

Another way to write this is KE = 0.5(mv2)

Where m = mass in kilos, and v = velocity in meters/sec

The result KE is in joules.

For the purposes of the game, we assume that 1000 kilojoules, or 1.0 megajoules, does 1 point of damage.

Also, we assume that per megaton of TNT equivalence, 4.184 x 1015 joules of energy is released in total. (NB: I still have to figure out how to apply this in the case of an exploding warhead. How does attenuation affect this?)

[14.11] Kinetic Weapons

Kinetic weapons deliver X damage to a target based on the base damage delivered plus the energy difference caused by the vectors of the firing vessel and the target. For example, two vessels hurtling towards each other at 2.2 kilometres per second would add that vector to the velocity of the fired slug, and the slug would deliver more damage.

[14.12] Missile Weapons

[14.13] Energy Weapons

[14.2] Sensing Calculation

Sensing Calculations are calculated based on arbitrary numbers derived from a loose extrapolation of today's technology.

The basic Chance to Detect is calculated by multiplying the Signature of the target with the Effectiveness of the sensor:

Cd = SE

Example: a radar with a Effectiveness of 0.75 tries to detect a target with a Signature of 0.5. The Chance to Detect is (0.75 * 0.5) or 0.375 = 37.5%

NB: Still working on attenuation rules for range. As you get closer, the attenuation value goes up on a logarithmic scale.

[15.0] Scenarios

[16.0] Glossary of Terms

Active Sensing: Emitting radiation/energy in an attempt to locate a target or resolve a contact through reflection. Radar and sonar are both active sensors. This often called pinging a target. Note that active sensing causes the sensing vessel to "light up" and reveal its location to passive enemy sensors.

Armour: Canadian/English spelling for "Armor" goddammit. Also, mass such as steel, composites, and other substances encasing vital systems on a vessel.

Colony: A human-occupied world in one of the many star systems explored by humanity in the late 21st century.

Contact: Sensor datum point that indicates the possible presence of a vessel or other object within detection range.

Delta Vee: Change of velocity, also the ability to change velocity as dictated by resources such as fuel and thrust.

Firing Solution: A series of calculations that direct a weapon to the successful interception of an enemy contact. Firing solutions are of course unnecessary for energy weapons.

Fleet: A group of up to twenty Human military spacecraft working as a unit; also, a synonym for the Human player(s) in a scenario.

Kinetic Weapon: A weapon that causes damage through the delivery of energy to the target imparted by a collision.

Handwavium: An overused but often useful element found in many science fiction novels that allows for plot-hooks and story development while avoiding the hairy business of explaining the actual math behind a proposed concept. Also found in science fiction games allowing for play balance.

Intruder: A menacing machine intelligence mandated to destroy all life in the Galaxy; also, the name of this cool game.

Passive Sensing: Data collection through non-emitting means, by "listening" on a variety of bands. Less reliable and less useful than active sensing, but does not reveal the location of the sensing vessel.

Prosecution: The resolution, pursuit and ultimate destruction of an enemy contact.

Resolving: Also "resolving a contact." Collecting data on a specific contact with the purpose of identifying as much detail on that contact as possible.

Resource Points: Points spent on the construction of Intruders and Fleets. Part of the internal game economy.

Squadron: A subset of a Fleet, usually a grouping of six or eight vessels with a specific mission, operating as a unit.

Strategy: The science of military command, or the science of projecting campaigns and directing great military movements; generalship. Short form: macromanagement.

Tactics: The science and art of disposing military and naval forces in order for battle, and performing military and naval evolutions. Short form: operations management. Micromanagement in this context is the command of a single ship.