A conversation on the Cortex boards got me thinking about a rules set missing from the Cortex books: Invention.  This can be especially handy in a Pulp or Victorian sci-fi setting where superscience is the norm, but also can be reflected in settings like Battlestar Galactica – where the crew built a new fighter from scratch.

So here’s my first pass at a set of Invention rules.  They are necessarily fast and loose, but should work to provide some kind of framework for the Cortex GM…

BASIC INVENTION RULES, Part 1 (Modifying Stuff):

First, figure out what the character is trying to do.  Is it a simple modification?  One that would be a simple test, like adding night sights to a firearm that allows for it (like Glock and most other new firearms) – that should be a straightforward Mechanical Engineer (Customize) test as Easy with a base time of 30 minutes.  Or does it require real work?  If the gunsmith had to work with an old Colt 1911 with fixed sights, they have to shave the old sights, drill and tap the slide for the new sights…that’s work.  And an extended test of Average and 6 hours base time per test.

Second, what skill(s) are needed?  Mechanical Engineering (Customize) works well for most gear situations, but for complex tests, there might be others needed.  The example above with the 1911 would require a Craft (Metalworking) test to modify the slide, followed by a final Mechanical Engineering (Customize) to set the sights properly.

Here are some examples of modifications and the skills that might be needed:

Increase Speed of a Vehicle: Mechanical Engineering (Customize) to change exhaust on a motorcycle or drop in a supercharger or turbocharger on a car, another test or maybe a Tech Engineering (Programming) to remap the fuel injection and other sensors issues.

Increase the accuracy or range of a gun: 50% increase in range or a +1 die step to skill check requires a Mechanical Engineering (Customize) or Guns (Gunsmithing) EASY to add a scope or lasersight.  To swap out a barrel or do action modifications for reliability or accuracy would be a AVERAGE test.

Alter rifle from semi to full-auto: Average Mechanical Engineering (Customize) or an Average Craft (Metalworking) to modify the sear, and an Easy Mech. Engineering (Customize to install.)

Increase magazine capacity on a gun: Craft (Metalworking) Average to build a new magazine design.

Increase range of vehicle: 50% increase is an Average Mechanical Engineering (Customize) that might involve a Tech Engineering (Programming) for the fuel map.

Adding weaponry to a vehicle: Just bolting a mount for a gun to the roof of your Toyota truck (a la the Somali “technicals”) is an Easy Mechanical Engineering (Customize).  Hiding 1.5″ free flight missiles in under the fog lamps of your 1986 Aston Martin V8 is another matter – there’s the mount for the missiles, the aiming systems (if any), and the electrics for the launchers, as well as blast protection for the motor.  That’s an extended test with a Hard Mech. Eng./Customize to design it, another to make the mechanical modifications, a third or Tech Engineering/Customize to set up the computer for target control and the windscreen HUD and radio knobs for aiming…

Third, how difficult is the modification?  If it’s something that just swaps out, bolts on, or otherwise is plug and play – EASY.  If minimal modifications need to be made, AVERAGE.  If it requires a redesign or fashioning of parts, HARD+.  If it requires design and manufacture of parts, as well as modifications to the original parts, FORMIDABLE+

Fourth, how long will it take?  Base times for simple tasks should never be more than 6 hours.  For extended tasks, the base time for an Easy task should be minutes; Average an hour to 4 hours; Hard 6 hours to a day; Formidable should be a day to a week; Heroic should be a week; Impossible and higher a month base time.  (For example: Designing and building the 1969 Ferrari Daytona – from paper to release was a matter of less than three months…)

It the inventor has a staff – the stereotypical single strange assistant (Igor), for instance –  they should receive a +1 die step to their skill.  For multiple assistants, add +2 skill step to the skill.