For a character to create a new invention takes two rolls: one to create a workable theory and one to create a workable prototype. Each has its own rules and its own timeline. Both rolls are done in secret by the GM.

Theory Creation

The first step in theory creation lies with the GM. They must decide all the required skills and supporting skills for the theory. The skill roll for the Theory equals the lowest character’s skill of the required skills. All skills rolls use a target number of 5. Supporting skills may add bonuses and are rolled at the level of the supporting skill. Please note that since supporting skills are additive, it is best for GM’s to only allow one or two supportive skills at most. The supportive skill roll may be rolled by the player. The number of successes required depends on the complexity of the device planned:

ComplexityExample Successes Required
MundaneGlue Gun, Iron1
SimpleBicycle, Garage door opener2
AverageGun, Steam Turbine3
ComplexRadio, Disease Cure4
ExtremeComputer, Automobile5
AmazingNueral implants, Anti-gravity6

Typically, one roll is allowed per day. Character’s with the Gadgeteer advantage may make a number of rolls equal to the level of their advantage. Extra successes can either reduce the number of successes needed on the prototype roll or reduce the time to create the theory. This is the player’s choice and determined before the GM rolls. A roll of all 1’s means that the character believes that they have created a workable theory. The Theory roll is also modified by the following penalties and bonuses:

Each tech level below the character’s known TL -1
Duplicating an available, working prototype +5
Harry’s hiding from the Nazi’s in a bombed out research facility high on a mountain. He can’t risk walking out so he decided to build a glider. He is not an Aeronautical Engineer, but he is a Mechanical Engineer with a Gadgeteer advantage of 4. The GM determines that a glider is a simple device. Harry’s Mechanical Engineering skill is 8, therefore to default to Aeronautical Engineering gives him 2 penalty dice. His gadgeteer advantage gives him 4 bonus dice. No other conditions apply. His final skill will be 8-2+4 and he will need 2 successes. Harry decides that creating the device well is more important than quickly, so he opts for the bonus dice on the roll. He achieves 4 success on the first roll and by the end of the first day, he has plans that seem very solid. He will subtract required Ss from the prototype roll. His plans are so good that he is guaranteed a success with 0 successes required.

Prototype Creation

When creating a prototype, the character must have an adequately stocked lab. If the lab is poorly stocked, then add 1 penalty dice. If the lab is well-stocked, add 1 bonus die. The same for funding: either a +1 well funded or a -1 if underfunded. Each week, the GM will roll for the character requiring the same number of successes as the theory creation as modified by the Theory roll. Before the roll, the player may determine whether extra success will reduce the prototype creation time or increase the quality of the item. If success go to reduce the time divide 7 days by the number of successes achieved.
Now that Harry has plans, he begins to make the glider. His lab is understocked and underfunded has 2 penalty dice to start. In addition, he has his gadgeteer advantage giving him +4. He determines that speed is more important here than quality, and so opts for a quicker creation of the item. Since building the device will use B/R Winged Vechicle, he has to default from his Mechanical Engineer skills again. This time, he must default at -2 skill from Aeronautical Engineering and -2 penalty from Mechanical Engineering. This totals 6-4+4. He rolls 4 successes against 0 required. Since he opted for speed the time to create the device takes him 7/4 days or a little under 2 days.