The Black Campbell

BASIC INVENTION RULES, Part 2 (Creating New Stuff):

Sometimes, your character just wants to build new stuff.  Maybe their battlestar needs new fighters you have to build from scratch.  Maybe you have to build a giant robot for nefarious purposes.  Maybe your character wants to invent the aether flyer…

Here’s some ideas on how to do that.

1) There are two stages to invention: design and construction.  Design is a simple test – a one-off roll against Mechanical Engineering/Create New Device, with the difficulty giving the base time.  An Easy test (building a a spring-loaded arm holster) would be a matter of minutes.  An Average (redesigning a motor or an existing piece of technology) might take a few hours.  A Hard task (redesigning an existing piece of tech to be better [50% more range, accuracy, a +1 step to a single attribute] ) would take a day or more.  Formidable tests (designing a new device with similarities to existing ones – like a simple wind-up mechanical man based on clockwork) would take days to a week.  Heroic tests (like designing a new vehicle type) would take a month.  Incredible tests (designing a new piece of technology requiring a new understanding of chemistry, physics, etc.) would take a base time of 6 months or more…

In the case of building something requiring a new kind of understanding of science itself – say the creation of an aether flyer in Victorian times or warp drive in a near future game, I would suggest a Complex test for the design phase – requiring a Science Expertise (Specialty) of Formidable or more, followed by the Create New Device test.

2) Construction: with the design phase is done and now it’s time to build your machine.  An extraordinary success in the design phase will give you a +2 die step to your skill tests at this stage of the game.  A failure of design does not mean a failure of the machine, but rather gives a -2 die step to the skill when building the device.  A botch in design means the thing won’t work; you have to go back to the drawing board…

First you need to know, is it a simple device or a complex one with multiple systems/elements?  The spring-loaded holster requires a leather greave with a sliding metal arm(s) and a spring assembly with some trigger mechanism – a trigger around the thumb or a catch sensitive to the movement of the arm.  Each piece, however, is relatively simple…a single Mechanical Engineering/Create Device test should be sufficient.

For more complex gadgets like weapons, an extended test might be required.  The difficulty should be based on whether the device is a knock-off of something already around (say a new revolver in the Victorian era), a new design (a semi-automatic in the Victorian era or a gauss weapon in modern times), something truly radical (a ray gun in the 1930s.)

A knock-off should be an Easy extended task, a new design that is not terribly radical an Average, a innovative design Hard, a completely new gadget Formidable with similar time schemes to the design phase, but with each test taking that amount of time.

Sample tests:

Fabricating a new firearm: Craft (Metalworking) Average x2, Mechanical Engineering/Create New Device x2, possibly Guns/Gunsmithing.

Creating a new weapons (ray gun): Craft (Metalworking), Technical Engineering (Electronics), Mechanical Engineering/Create New Device.

Creating a smoke bomb marble: Science Expert/Chemistry, Craft/Glass Blowing, Mechanical Engineering/Create New Device

Creating a starlight vision system: Craft/Optics x2, Mechanical Engineering/Create New Device, possibly Technical Engineering/Electronics.

Building a pre-fab house: Craft/Carpentry x2, Mechanical Engineering/Construction x1, Mechanical Engineering/Plumbing x1.

For vehicles, there are some rules in Serenity that can be modified for use.  Figure out what the Attributes of the vehicle are (you can look at examples of vehicles in the core Cortex book), their skills, traits and flaws, etc.  Add the dice for the attributes, skills, speed (where applicable) and traits together to get the basic complexity of the device.  Failures in the design phase here get added (add the number of points the target for design was missed by.  I like the idea of turning this into flaws.)

2-12: Very Low Complexity.  Costs are x0.4 a similar device/vehicle.  Test difficulty – Easy.
13-20: Low Complexity.  Cost is x0.6 a similar device/vehicle.  Test Difficulty – Average
21-26: Average Complexity.  Test Difficulty – Hard
27-42: High Complexity.  Cost: 1.6 a similar device/vehicle.  Test Difficult – Formidable
43-48: Very High Complexity.  Cost: x2.4 a similar device/vehicle.  Test Difficulty – Heroic.
49+: Extreme Complexity.  Cost: x4 a similar device/vehicle.  Test Difficulty – Incredible or more.

Example: Dex – a mechanic in 1936 –  wants to build a jet pack for his Jackie, an axiatrix he works for.  The design phase sees him learning rocketry (a new science) – Hard Science/Physical.  He rolls his d12 Intellect and d6 Science and gets a 12 (success!) He designs the pack’s attributes: AGL d2 STR d4   VIT d2   ALE d0   INT d0 WIL d4.  Speed 3.  There are no skills, but he has given it a Flaw of Complex Needs d2 for the special fuel it uses.  Total: 17 – low complexity.  Normally, this would be a Hard d12 INT and d10 Mechanical Engineering/Create New Devices test, but it’s a brand new technology, so the GM raises the design difficulty to Formidable.  Dex rolls and scores a 22!  Extraordinary success!

Now he has to get to the construction phase.  This is an extended test.  With the extra success, he gets a +2 skill step to the tests.  The design phase is past and the complexity gives a difficulty of HARD.  Dex needs to get a total of 55 in his tests.  Each test takes a day.  He rolls his Craft of d10 (that’s with the +2 skill step) and Agility of d6 and fails with a 4, but the next test is a success of 11.  The formation of the metal casings took two days and he has a total of 11 (the failure didn’t count toward the total points.)  Mechanical Engineering/Plumbing to run the pipes for fuel, the storage tanks, etc. and Dex rolls his INT d12 and Mech Engineering d6 (now a d10 with the success step) and gets a 13.  Success and the total is now 24.  Mechanical Engineering/Create New Devices (he has a temporary d12+d2 from his design success) tests sees an 11, 7, and 18.  It’s been 7 days since he laid pencil to paper and he’s at 52 points.  The GM decirdes to have him test an INT+Craft/ Leatherworking (d12+d10) to create special trousers to ablate heat and flame from the pack.  Dex rolls an 22.  He’s done at 8 days and the GM decides the work on the flight outfit is flame proof, and that a quickly cobbled together helmet and jacket gives Jackie a 2W armor for combat or in the event of a crash.

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.