These New Skills are Taken directly from an old accessory, which you will probably see me update a lot of old accessories for 5e over the course of the next while…

These skills are taken directly from “PC2: Creature Crucibles: Top Ballista” by Carl Sergeant

This book is really the only source of information of the Flying City of Serraine, and the Gnomes that run it.

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Fantasy Physics (Wisdom skill)

This is a unique skill to gnomes and a very few nagpa. It is the ability to design a device for carrying out some relatively complex function based on a pseudo-technological theory. Fantasy Physics is the principle that if something looks as if it ought to work. Even though its workings may not actually be entirely possible, the odds are that it will work.

Machine Building (Intelligence skill)

This is unique to gnomes and cannot be readily taught to others. It is the practical complement to Fantasy Physics — while that skill is the theory and principles, this is the practice. It is the ability to take a Fantastic-Physics construct and make it in accordance with the principles of Fantasy Physics.

New Skills

Gnome Construction Skills:

Sky-gnomes are great designers and builders of machines and contraptions of all kinds. Taking a healthy interest in such matters is an absolute must for a PC sky-gnome. Follow the steps below when developing a new device.

Stage l: What is the Machine For?
Decide exactly what the machine is to do. It may have more than one function, but it’s best to stick to machines with relatively simple purposes.

Example: A player decides that his gnome player creature is going to attempt to design a form of hovercraft, capable of carrying up to six normal-sized creatures. This player has always wanted a magical flying carpet, has never found one, and feels he now has the chance to make a workable substitute.

Stage 2: Planning the Design
The player must come up with the basic principle which is going to be used in the design of the machine. He must specify whether the essential function of the machine will be carried out by either pure technology, magic, or a mixture of the two. Important Note: If magic is to be a part of a design, the inventor must be a Wizard, Warlock, or Sorcerer! Otherwise, the machine will not work!

The basic principle is the central idea behind the machine’s functioning. This need not be a detailed nuts and bolts explanation. Adding eccentric detail is acceptable, however. The point to keep in mind is that of Fantasy Physics. The functional principle needs to appear reasonable. The details don ‘t matter! The following are examples of invention power sources taken from The Book of Wondrous Inventions, a must-have book for the would-be gnomish inventor.

Golem-Muscle: A golem (or several golems) turn cranks to make this device operate. Powerful, but cumbersome, space intensive and best for slow action.

Pedal Transmission: One to 100 gnomes pump the pedals to make the device work. Cheap, but unreliable. Even gnomes get tired of pedaling.

Spring-Load: A large metal spring slowly unwinds, driving the device to which it is attached.

Steam-Power: This technology consists of heating water in an enclosed area in order to build up steam pressure, which drives machinery as it is released. Steam machines are heavy, hot, complicated and usually require a minimum of four engineers to operate. Steam boilers have a tendency to explode.

Wind-cycle: Bags or sails catch the wind, rotate machinery and power the device. Speed and power of the effects depend upon wind speed.

Entrapped magical energy: Magical energy (or an energy creature like a fire elemental) is entrapped in a storage device. Energy release powers the invention.

Example: The player decides that Ibadullah Cogtweaker, his gnome PC (who is a Wizard), will use a magical principle combining air and fire Elementals to provide the motive force for the hovercraft. This is a superficially plausible idea, and thus is entirely consistent with Fantasy Physics. It is a Pure Magic design principle. The details do NOT matter.

Stage 3: Determining Whether it Works
The DM needs to decide whether or not he will allow the device to function as designed. This is basically a common sense interpretation of the Fantasy Physics skill. If, given a healthy dose of imagination, it seems like a device might work, then it will! On the other hand, this does not mean that it can be built!

Stage 4: How Difficult is this Going to Be?
Now, the DM needs to figure out how easy or difficult this design is going to be. Table 14 lists a selection of modifiers that will affect the character’s chance to successfully construct his invention.

Table 1. Design Complexity, Skill Modifier, and Time needed for Designs
Design                     Challenge         Time
Complexity              Rating              Required
Easy                        10                    1d4 days
Simple                     12                    1d4+2 days
Tricky                      15                    3d6 Days
Difficult                   18                    5d6 days
Very Difficult           20(or more)       30+7d10 days

Extenuating Circumstances
No Fantasy Physics skill       +4 Challenge
Meddling Special Ability      -2 Challenge
No Meddling Box                 +2 Challenge
Distractions                          +1 ~ +4 Challenge

The DM needs to determine the invention’s innate complexity and decide which (if any) extenuating circumstances will affect its successful completion. The applicable Challenge modifiers are totaled together.

Design Complexity: To determine an invention’s difficulty level, the DM needs to decide not so much the difficulty of the basic concept — which should always be simple — but the difficulty of putting it into practice. Much depends on the scale of the enterprise (a hovercraft is hardly a small thing to design and build) and how radical the effects of the creation will be on his game campaign (a hovercraft is a very unusual and rather powerful machine, and would grant the gnome a very useful mode of travel), To design a really useful, sizeable machine is significantly harder than designing something small and fairly conventional.

Example: The DM rules that Ibadullah ‘s attempt to design a hovercraft is a Difficult design attempt. By way of comparison, the same DM rules that a second design Ibadulla has submitted – for a steam- powered combined Turkey Plucker, Gutter, and Stuffer — is Simple (because if it works it isn’t going to change the world or the campaign much, and the DM likes the idea, Such subjectivity is permitted.)

Extenuating Circumstances: These are the presence or lack of skills, abilities or devices that influence the construction of gnomish inventions. Fantasy Physics is covered in this chapter. The Meddling ability can be found in the Gnomes section of this book. The meddling box can be found in the “New Equipment ” section (Detailed later). Distractions are things that keep the gnome from either continuous work on his design or that keep him from concentrating. Adventuring is an example of an interruption. Developing a design in a rowdy tavern or in a home where squalling gnomelings take a gnome’s mind off the task at hand are examples of concentration distractions. The exact penalty is up to the DM.

Time Required: This is the time that must be spent by the gnome in design work. The gnome doesn’t have to spend every waking hour doing this work, but he can’t spend much time doing anything else (no adventuring!) and will need a quiet place in which to work.

Stage 5: Does it Work?
Having determined the total difficulty modifications, the DM now makes a secret Fantasy Physics Check for the gnome, Using the challenge rating from Table 14.

Importantly, the gnome always thinks that his design is sound. Only the DM knows, at this stage, whether it actually is sound or not. Sound or not, don ‘t tell the player!

Stage 6: Building the Contraption
While the Fantasy Physics skill is important to design a machine of some sort, the Machine Building (Intelligence) skill is most important for actually building it. While the designer need not be the chief builder (the person actually in charge of the project), it is also important that the gnome who designed a machine should be involved in its construction!

Again the DM must decide several factors regarding the project. First, consider the scale of the project, If the project involves building a sizeable machine (as is the case with the hovercraft in the examples), the DM should break this down into a series of stages, each of which requires a separate successful ability check (detailed later). A second crucial qualifier is that if the design uses magic, the chief builder must be a Wizard, Warlock, or Sorcerer of 9th level or better. It is best if he is also personally able to cast the spells that go into its construction.

Example: The DM decides that a hovercraft is no simple project and decides on three stages:
(i) building a chassis;
(ii) building the superstructure;
(iii) bolting in the magical stuff (Elementals, etc.).

If the machine appears to be complex (intricate, has many functions, etc.) the DM can add further stages. Since each one means another ability check, this simulates the increasing difficulty of building a complex or multifunctional device.

At each stage of the building, make a skill check with the chief builder’s Machine Building to deter mine success. Apply these modifiers, as appropriate, to each check:

Use the Base Challenge Rating for design complexity from Table 14 above.
CR +6 if the chief builder doesn’t have the Machine Building skill;
CR +2 if the chief builder didn’t actually design the machine;
CR -1 if the designer can actually build the machine on his own with no required assistance;
CR  +4 if the builders do not have a set of skyhooks (see “New Equipment”) to work with;
CR +2 (or more) if no skygnome labor is available to build the machine;
CR +4 if the machine uses magic and no Spellcaster is to hand.
CR +4 if a Spellcaster other than the chief builder casts any necessary spells into the device;
CR +3 if this is a Rush Job being completed faster than it reasonably should be.

This looks a long, tiresome list but only a small number of the modifiers will apply in any given case.

Stage 7: How Long Does This All Take?
The time required is also important. Each stage in the construction takes 11-30 gnome days as a base figurea One gnome working for one day is a gnome day. Ten gnomes working for one day is 10 gnome days. The DM can add to this if rare components are needed, or the work is intricate, etc. A rush job can halve this time, but adds a +3 penalty modifier to the dice roll at each stage of construction.

Stage 8: How Much is this Gonna Cost?
The matter of cost is also important. Building at each stage requires wages for the skygnome builders, the cost of employing a Spellcaster, cost for raw materials, cost of use of the design studio, and lots of little extras which just add up. Some designs will use much more expensive components than others, of course. For instance, a mean DM could rule that Ibadullah’s design needs insulation achievable only with red dragon hide, available at only 1,000 gp per square foot, and that (say) 100 square feet should do the job. The DM should come up with a figure which will hurt the gnome’s pocket without bankrupting him.

In the case of magic, the DM will need to decide what level of magic use is involved. A Spellcaster capable of using magic of this level must be available or else the design cannot be created!

At each stage of building, the DM determines success or failure with a Machine Building check for the chief builder. If the result is successful, work can proceed on the next stage. If not…

Stage 9: Why Didn’t it work?
If the result is failure, this will usually be apparent. The reasons for the failure will be known if the designer makes a DC 15 Fantasy Physics Check, and the chief builder makes a DC Machine Building check (at a +4 penalty if he doesn’t have the Machine Building skill). If this happens, another stab can be made at building correctly. Success with both these Skill Checks can reveal that the entire design is flawed (i.e., the DM determined way back in Stage 5 that the thing wouldn’t work). First time around, something obviously wasn’t quite right with the way the design was translated into a construction. If this second attempt fails, it is realized that the design has not worked out in practice — even though it may be worked sound in theory. A new design will have to be made. Back to the drawing board (Stage 2)!

Finally, if all the ability checks are made, the machine can be wheeled (or dragged) out for the adulation of one’s fellow gnomes!

Example: Ibadullah oversees the production of his own design (the DM rules that he cannot possibly build a hovercraft on his own). He has Intelligence 15 (+2), and a Machine Building skill, a team of 5 gnomes to do the work for him, and a 9th-level Wizard on hand for the magical stuff

The first stage is building the chassis. This will take 15 gnome-days, the DM decides, and so the gnomes can do it in 3 days. Ibadullah is his own chief builder and makes a Machine Building check with a +2 modifier. The penalty is applied because the design was a Difficult one — this is carried over from the design stage. The DM rolls 7, which is adjusted to 19. No problem; the chassis is built soundly.

The next part of the construction is the superstructure. This is going to include the controls needed for modulating the magically-driven part of the craft, so magic is involved. Conjuring elementals requires the use of a 5th-level spell, and fortunately the foresighted Ibadullah has a 9th-level Wizard on hand to do his stuff Again, the die difficulty is 20 because of the difficulty of the design and because Ibadullah is not casting the spells himself. However, the DM does an extra bit of creative reasoning from the list of modifiers. The 9th-level Wicca has to act as joint chief builder, the DM reckons, so +2 modifier for the chief builder not being the designer is applied: CR is now 21

This turns out to be critical. The d20 roll is 6, modified up to 18. Ibadullah has blown it; after 20 gnome-days work, it’s clear the design is not sound. Ibadullah and his Wizard try to reason out what’s gone wrong here. Ibadullah has to make a Fantasy Physics Check and rolls 19; the Wizard has to make a Machine Building Check at or above the Difficulty of 18. The DM applies half the usual +6 penalty to the Wizard’s check (he does not actually have the Machine Building skill!) since he is joint chief builder. The die roll for him is 14, adjusted upward to 24 — just made it! The DM makes Ibadullah ‘s player sweat by telling him how the Wizard needs a couple of extra days to try to figure out what the problem is, he can almost see the reason but not quite — the workers want more money, one or two are bored and starting to drink too much, and Ibadullah is getting very anxious. But the Wizard comes up with the goods.

Given this, another stab can be made at slightly revamping the second-stage design and building, and this time — with a d20 roll of 14 for Ibadullah — it works! The physical assembly of the machine is ready for the final stage.

Unfortunately this is not going to be easy. The 9th- level Wizard is now the effective chief builder, since only he can handle elemental-conjuring magic. The modifiers which apply to this final stage are: +6 (the Wicca has no Machine Building skill); + 2 (the Wicca didn ‘t actually design the machine); with a base of 18 (the design was Difficult anyway). On the other hand, as the chief builder, he is no longer penalized when he casts his spells.

That’s a CR of 26, a really hard roll to make. The DM allows the player to make the final d20 roll, having told him he needs to roll 16 or higher. The player rolls — a 19! The machine finally works!

As should be clear, it isn ‘t going to be easy to devise and build machines, but then no DM is likely to want lots of magical- technological, powerful machines like hovercraft dominating his campaign anyway. The rules provided here make it easy for gnomes to come up with intriguing, eccentric, oddball things, but significantly harder to make complex and powerful contraptions. Even when they work (as in the case of the hovercraft above), the DM can keep them from dominating the campaign in many ways. Consider the hovercraft case. The DM could fairly rule that:

• Flying time is limited (4 hours or less per day);
• Some form of magical fuel must be supplied (maybe a fireball or wall of fire spell must be used to ‘charge’ the elementals each day);
• There is a 1% chance per day that some small part falls off the machine, with a 50% chance that this halves flying time and requires maintenance (if not done, the next fallen part grounds the machine);
• flying over sandy terrain will ruin the machine and prevent it working, and so on.

The DM should not restrict things unduly, but machines shouldn’t dominate the game. The DM should perhaps consider pointing out the limitations on machine function to a player at the design stage, so the player doesn’t feel cheated.

Machines and contraptions can be great fun for players to dream up and attempt to build. They can also become adventure hooks, as an eager gnome seeks out some magical skyhooks or a renowned teacher and designer, or some dragonskin insulation for the inside of his salamander-powered steam train which tends to get rather over hot in the engine room!