Houses Are People Houses Are People

Old school roleplay musings

Engineer Class


Engineers are crafters of all things non-magical. Some are smiths, some carpenters, some architects, some leatherworkers. They’re always on the watch for useful things that don’t necessarily seem useful, and for things to deconstruct for their wonderful bits.

For context, see how classes and leveling work in this earlier post. Terse summary: Gain 1 template per level until level 4.

Class: Engineer

Starting Equipment: leather armor, hammer, scissors, dagger Starting Skill: see profession below. You also gain the engineer skill when you take your first Engineer template.

A: Craft, Identify, Salvage

B: Repair, Improve

C: Traps

D: Modify

You gain 1 blueprint for each Engineer template you possess. Use the process for rolling on the blueprint tables to create each blueprint.


A: Craft

When you have access to a market that meets your needs, you may spend 3dx*10 GP (x = expense as determined by the referee) to fill in the gaps in whatever you are trying to build. (Change to 3dx*100 if you hand out gold at a more traditional rate than I do. I use Skerples’ currency.)


Identify any non-magical item by examining it for 10 minutes. You can get an inkling of the item’s magical purpose if you roll a 1 on a d6 after 10 minutes of examination. (This doesn’t apply to purely magical things like spell scrolls, potions, wands, etc.)


You can deconstruct objects for materials and components. Most materials and components do not use inventory slots.

B: Repair

You may spend 3dx*10 GP (x = expense as determined by the referee) to repair an item. The next two salvage actions gain a broken item generated in the same way as a blueprint. The GM should make sure the item suits the salvage.

There is a 1-in-6 chance of finding a repairable broken item when searching an area that the referee believes might contain such a thing.


Improve any item by one point (only once per item) by paying 50% of the market value of the item. For example, a sword that would sell for 20GP can increase its damage by +1 by paying a cost of 10GP.

Any weapon improved in this way also improves its breakage rating by one. For example, a fragile weapon would become a standard weapon and a standard weapon would become a masterwork weapon.

C: Traps

If it’s at all reasonable that a genius engineer could combine the components and items you have into a trap, you can do it. You may spend 3dx*10 GP (x = expense as determined by the referee) to fill in the gaps.

D: Modify

Alter items you own if you have learned a way to do so. Blueprints often provide access to a process for modifying items.

If you can explain how you use materials to modify an item in detail and it makes sense, you’ve modified an item. Anyone can do this, not just engineers. For example: “I’m going to use my glue to attach my string to my pole” results in a string on the end of a pole.

Blueprint modifications are different. They provide ways to do things that only an expert engineer would understand.

Breakage rules from my main OSR rules document (Village Folk) for your reference:

Check for weapon breakage if ATK roll = natural 19 or 20. Check for armor breakage if DEF roll = natural 19 or 20.

Breakage Rating

Fragile weapons always break. Standard weapons = 3-in-6 chance on d6. Masterwork weapons = 1-in-6 chance on d6. First break = -1 to ATK. Second break = useless.

Armor break = -1 to DEF per break. Useless when penalty equals the bonus.


D4 Skill Additional starting items
1 Architect Blank book, ink, quill
2 Smith Hammer, tongs
3 Carpenter Handsaw, hammer, nails
4 Leatherworker Needle, spool of thread, knife

Blueprint Generation


  1. Roll a blueprint type
  2. Roll a blueprint verb
  3. Roll a blueprint object
  4. Describe an item that fits the above results.
  5. Start over if the result isn’t interesting or seems impossible to craft. Weird is good. Don’t reroll when it’s weird.

The player character should now be on the watch for items and components that might be used to create something resembling the blueprint. The referee should be somewhat lenient in deciding whether a combination of parts will work. Engineers are brilliant at makeshift, piecemeal improvisation.

If the engineer doesn’t have relevant magical knowledge, their craftsmanship will not apply magic. Use mechanical and physical knowledge instead. They might be able to think of a way to use a magical artifact in the creation of an item, however. If an item seems impossible to craft, roll a different item.

Example 1

Type: clothing/armor

Verb: gather

Object: poison

A plan to build a glove that extracts poison from the hand of the wearer into a 10ml vial. This glove also reduces the effect of any poison the wearer suffers by 12.

Components could include bits of plants or preserved animal bits that can suck, leech, or absorb liquid, piercing objects that might be formed into a syringe or needle, a vial or something similar, a glove, leather, fabric, metal, etc.

The plan doesn’t have to be built exactly to specifications. The player might think of some other way to build something nearly the same as this glove yet different in some way. Don’t spoil that creativity.

Example 2

Type: clothing/armor

Verb: defile

Object: thought

A hat that invades the wearer’s mind with horrible thoughts they wouldn’t normally have. The engineer might sell the hat to an enemy who would then start having to deal with thoughts opposite to what they would normally think.

An evil, selfish character might keep having great ideas about how to prevent world hunger. A humble priest who only serves the church might start thinking about stealing from the treasury or fantasize about how much fun it would be to claim to be an atheist.

D4 Item Type
1 Accessory
2 Clothing/Armor
3 Weapon
4 Other (a disc, free-standing machine, orb, box, etc)
D30 Verb
1 Create
2 Destroy
3 Detect/Sense
4 Obscure
5 Defile
6 Neutralize
7 Bend/Warp/Shape
8 Command/Geas/Charm
9 Push/Pull
10 Move/Teleport
11 Gather
12 Channel
13 Condense
14 Automate
15 Divide/Open/Split/Separate (second roll on object table optional)
16 Preserve
17 Reposition
18 Speak with
19 Increase/Amplify
20 Decrease
21 Destabilize
22 Delay
23 Hasten
24 Hold
25 See
26 Open
27 Close
28 Endure
29 Convert (roll object) to (roll object)
30 Infect (roll object) with (roll object)
D30 Object
1 Appearance
2 Light
3 Water
4 Time
5 Thought
6 Cold
7 Heat
8 Sound
9 Size
10 Poison
11 Air
12 Fire
13 Wood
14 Stone
15 Non-precious Metal
16 Precious Metal
17 Plant
18 Magic
19 Dead/Death
20 Earth
21 Disease/Spoil
22 Flesh
23 Bone
24 Door
25 Fur/Hair
26 Animal (name a broad kind)
27 Food/Hunger
28 Dream
29 Creature (roll on creature table)
30 Emotion (Roll on the Blueprint Emotions table)

(Only necessary if Emotion was rolled on the Object table)

D12 Emotions
1 Frustration
2 Critique
3 Comfort
4 Amity
5 Peace
6 Fear
7 Anger
8 Pleasure
10 Pain
11 Confusion
12 Obsession