Shadowrun Gaussian Based will be a SR4 total rules conversion based on Gaussian distributions.

The basic random number generator will be 3d20 - 31 (or two green positive d20 a red negative d20 - 10) or a simple cell phone app.
The 3d20 are an approximation of a Gaussian distribution with mean 0 and standard deviation of 10.
The java cellphone app just outputs a true 0/10 gaussian distribution.

Goals of the system are:

Unified rules, which can handle a lot of different situations with generalized concepts (e.g. Sensors in vehicles are the same as in gear as in cyberware, the size ist just different).
Specialized rules do not change the balance of more general rules but add deviations from the mean (surgery rules do not in the mean, add to the cost of cyberware, but give detail on how to spend more or less money on that part of the cyberware experience)
Complete rule set (you can always have more specialized rules, but see above).
Every action should have a counter action included (magical search, cyberware scanning . . .)
Result of skill tests should be realistic (gaussian) and easy to estimate (in the mean the gaussian die adds 0).


Generalized balanced cyberware system (excel sheet that lets you generate your own cyberware, like "cyber muscle replacement that gives +x on strength and +y on agility").
Generalized balanced ki power system.
Generalized balanced weapon creation system.
Generalized balanced spell creation system.

Complex but not complicated rules.
Use of complex functions in sheets and character creation (done by a sheet), easy math during game play.

Use of opensource software:
- openoffice for character sheets (including the generators).
- tex for rules
- java for cellphone apps
- python for pc apps

I will recycle my DHGB (Dark Heresy Gaussian Based) rule set for SRGB:
If you want an impression on how the rules will look like, read those (some 100 pages).

grab the rules pdf here
and the whole pack with rules charsheet (for openoffice, implements the complex functions in character creation for you) and other stuff here

I will use this thread as my notepad to discuss concepts and game mechanics.

Interesting and usable, overall.

Pros :-

Lots of hard work have produced something that's a good conversion for people who like the W40K universe, but want different rules.
Good spellchecking/grammer [though not 100%], something that automatically makes it more "professional" and usable.
Nicely hyperlinked, so navigation is straightforward and useful.
You've done what most people only talk about, but never actually do.

Cons;-

Too many tables for my taste...
Too much maths for my taste...
Not structured/laid out in the most easy-to-read manner.

I'd move the list of tables to the front, as a secondary index, to make it more useful.
I'd also provide some background to the game, rather than make it rules only.
Examples ??

Not for me, in the end, but that's a rules choice [I prefer my own, for virtually everything] - not a final critique of what you've done.

Thanks for the feedback.

The DHGB rules have no fluff, because they itself are a total rules conversion of the Dark Heresy system by Fantasy Flight Games.
My SRGB rules will also have next to no fluff, as you can always buy the SR4 books for that. So its just about the rules.

First Discussion: Attributes, Skills and Basic concepts.

SRGB will use the following attributes:


Physical:
Agility (How agile your body is and how fast it can move)
Coordination (how good your hand-eye and body coordination is)
Strength (how strong your body is. This is a quantitative quantity, i.e. dragons and humans will have extremely different strength values)
Toughness (how tough your body is. This is a qualitative quantity, meaning a dragon and a human will have comparable constitution. Only together with the weight the constitution gives how much damage you can take)

Mental:
Empathy (how good you are at social activities. This quantity will go down when you implant ware)
Intuition (how good you are at perceiving things and making subconscious decisions. Animals can have high intuition values)
Logic (how good you are at pure logical thinking. Animals have next to no logic rating)
Willpower (how good you are at keeping yourself from temptations, withstanding pain and other negative stuff)

Extra:
Edge (how often you can re-roll stuff or enhance rolls)
Weight (the weight of your character, influences maximum number of hit points and wound limits (both in conjunction with constitution) how high you can jump, how fast you can run (both in conjunction with strength) and so on)
Magic (how good you are at sixth world stuff, goes down with implanting ware just like empathy)


The base rating for a humans in all mental and physical attributes is 20.

You do skill tests and attribute test by rolling the dG, the Gaussian die, either by using the cellphone app, or 3d20-31 or using two positive d20 and a negative d20 and subtracting 10.
The physical dice are only an approximation to the Gaussian distribution and have a mean of 0.5 instead of 0, but they will do. Both variants have a standard deviation of 10, which means that 68% of the rolls will be between -10 and 10, 95% between -20 and 20 and 99% between -30 and 30 (using physical dice, the extreme numbers to toll are around -30 and 30).

The skill test works like this:

dG +skill +modifiers -difficulty = Y

Y is the quality of the test. If Y is positive the test was passed. The higher Y is, the better the test was passed. If Y is negative the test was a failure. The more negative Y is the worse the failure is.

Attribute tests work in a similar way:

dG + attributemodifier +modifiers -difficulty = Y

The attribute modifier (which is also used to modify skill ratings which are connected to that attribute, see below) is calculated by using a logarithm with a base of 2 normalized such, that an attribute of 20 has a modifier of 0:

attribute modifier = 20 * (log2(attribute)-log2(20))

Dont worry, wou will never ever have to calculate this for yourself, this si done automatically by the character sheet for you.
Why is this? Imagine an opposed strength test between say a human and a human (Str 20 and 26) and a dragon and a dragon (Str 200 and 260).

If we used the raw ratings to do the tests, the test between the humans would be interesting. The first guy could have rolled a 8 and the second guy a -2 and the result would have been 28 to 24.
The case with the dragons, although they have exactly the same relative ratings, is different. The weaker dragon would have to cover a difference of 60 in attributes with the same die, the weaker human has to use to cover a difference of only 6. The chances are much worse, i.e. this system would not scale.

Lets look at the attribute modifiers:

Human Str 20: StrMod = 0
Human Str 26: StrMod = 8

Dragon Str 200: Strmod = 66
Dragon Str 200: Strmod = 74

The difference is always 8. This system scales. Note that a multiplication of the attribute by 2 results in a modifier difference of 20, i.e. an opposed agility test between X and X*2 agility values is always a difference of 20 in the test, no matter how small or big the values are.

We now have a system where we can simulate test between humans, dragons and cockroaches if we want to, without the system breaking down on any scale. Furthermore, the system gives realistic results, unlike the well known "lift from the back, Rogar" effect in linear dice roll systems, where the weak elf is able to push open a door that the strong barbarian isnt able to.
Of course this can also happen in a gaussian system, but the probabilities are much smaller and more "realistic".

Now how are attributes affecting skills?
Attribute modifiers are added to a skill value depending on the skill. For example shooting is heavily influenced by the characters coordination attribute and to a minor extent influenced by the characters agility. In case of close combat its the other way round.
On the other hand, some skills are only marginally affected by attributes (for example knowledge kills, which benefit from a high logic rating, but by far not as much as shooting does benefit from a high coordination value).
To reflect this, every skill has its own attribute matrix. For the above mentioned skills this could look like:

Shooting = ShootingSkill + (AgilityMod+2*CoordinationMod)/3
Knowledge = KnowledgeSkill + 0.5*(LogicMod)

Again, dont worry about the math, the charactersheet will do all this for you.

Baselines:

As mentioned above, SRGB will be baselined to a human with an average attribute rating of 20.



Cybered up characters will be able to reach a rating of 60 from start when spending a lot of resources on it.
Trolls, with an average height of 2.5 meters will, following well established scaling rules taken from nature, have a much higher base strength:

weight = height^3
str = height^2
str = weight^(2/3)

As the average human will be 175 cm, 70 kg, 20 Str. The average Troll will be:

height = 250 cm (defined by setting)
weight = (250/175)^3*75 ~ 220 kg (plus 25% because they are much more powerfully built on average = 250)
Str = (250/175)^2*20 = 40 (plus 25% = 50)

Dwarves will need some "they have denser and better muscles" arguments to get them up to speed.


Skills will be baselined a s such:



A legend with good cyberware might even be able to reach the skill-rating of 100 (including attribute mods with highly cybered attributes and skill boosting cyberware).

Note that the result Y in skill tests will not be just a number but will be used. Along with the quality Y goes the multiplier X, which doubles every time your quality surpasses mulitples of 10:



The quality is used for example to determine the time a skill test takes. Just divide the base time by X. This also means that skill test scales effectively. Going from 12 to 21 in resulting quality in a skill test doubles your effectiveness just like going from 52 to 61.
If you would just divide by Y instead of X, going from 12 to 21 would double your effectiveness (21/21 ~ 2) but going from 52 to 61 wouldnt do much anymore (61/52 ~1.2).

The quality can also be used to determine the effectiveness of the resulting test. In combat the damage done will be multiplied by X.
A hit with Y between 0 and 9 will be just a glancing blow ( only 1 time the damage), while a hit with Y between 30 and 39 will do 8 times the damage. In this way, combat between equally skilled foes is very exciting, while superior combatants can dispatch low-skill enemies very fast.

SR3 implemented a similar system where damage scaled up exponentially, too, if you remember the L,M,S damage which also doubled in every quality step (2 hits on the test).

This concludes my review of basic game mechanics.

Damn, I clicked here hoping for ShadowRun GameBoy.

So you're using a gaussian-based system to have a more predictable system with little deviation?
The idea of putting a lot of math in the character sheets and leave as little as possible in game is interesting, but I'm not sure how the 3D20-31 (or 2D20-1D20) will feel in game. Rolling with a cellphone app isn't very popular among gamers.

After installing a basic skill test sytem one has to choose how different environmental variables are going to influence a skill test.
Environmental modifiers include lighting, time available, wounds, and, most important gear.
In the case of Shadowrun, 3 types of gear in the most general sense instantly spring to mind: Spells, progrmams and other tools.

There are three basic ways to handle the effect of things:

* add a number to the skill test (most often used to approximate environmental effects, tools)
* directly modify the result of the test (ie the blast radius of an area spell, damage of a weapon, vision enhancement)
* cap the result of a skill test depending on the tool (used in spell test in SR4)

In SRGB we will use options 1 and 2. Option 1 for general tools, which just thelp the user to do a task better, and option 2 for task that are heavily dependent on the tool.

Option 1 will be used for:
Spells
Programs
General Tools
Some Ware

Option2 will be used for:
Weapons
Some Ware


This establishes a basic plattform to unify both real space, astral space and matrix space. The will differ in the attributes and skills used, but the basic game mechanics will be the same.




An attack (closed combat) of combatant A versus combatant B will work like this in all spaces:

combatskillA + modA - combatskillB - modB = Y

If the quality Y is 0 or more, B was hit. The damage is multiplied by X (see earlier post).

The only difference between astral space, real space and matrix space is the skill used.



The damage is simply related to Strength (which is Empathy in astral space and System in matrix space).

Of course, there will also be armed combat in all 3 spaces, which will use weapons (real space), wepaon foki (astral space) and weapon programms (matrix space). The only difference is the skill used (weaponskill, FocalCombat, CyberCombat+Attack/DefenseProgram), and the damage depends also on the weapon and Strength (or only the weapon in case of real space ranged combat.

Combat tests are allways opposed tests



A characters Toughness in conjunction with his Weight (Magic, Processor) determines his Life and WoundLimit (the threshold where the character is affected by more permanent wounds).