I've been interested for some time in the mechanics of making things in Risus, or of adding features (cliches) or improvements (dice) to existing things.
My theory so far is based on the Risusiverse article on healing: "When the Cure is Worse than the Disease", wherein a Risus healer character can engage in combat with another character's injury (dice = severity), and heal (remove the cliche for) the injury if the attempt is successful.
The combat-based mechanic below is partly due to this "healing combat" model, but also because I was primarily envisioning situations in which there was a need for some element of risk and/or dramatic tension.
The risk involved in combat also seemed a possible balance point for PC's inclined to create a whole bunch of narratively-significant entities (since they have dice). "I can rally troops with my Famous Warrior (3) cliche? I rally 6,000 Minions, at (2)!"
Here we'll be looking at two cases:
Artisans, alchemists and ninjas - making things
Sieges and home decor - improvements and additions
Case 1 - Making Things
Roll cliche v. dice of difficulty for the thing made, in an extended ("combat") conflict, to create the item.
If the PC wins the "combat," the item is created, possibly with its dice reduced to the dice the PC has remaining.
Each roll might, depending on circumstance, represent a certain amount of time or resources taken (10 minutes, a day, pile of sticks, etc.). This could be used to add balance and tension if, say, Orcs (7) are creeping up as the Fiendish Rogue (5) sets out a devious Snare (4).
Pumping, special equipment, questing dice, etc. could be used as appropriate, representing extra effort and the like.
e.g. a Ninja (3) attempts to set a Spiky Death Trap (Difficulty: 3). After several rolls, the difficulty cliche for trap-creation has 0 remaining dice, while the Ninja has 2. The result is a Spiky Death Trap (2). An Apprentice Potter (1) could attempt to make a Useable Cup (1) in the same way, or a Master Alchemist (5) could attempt to create the Philosopher's Stone (12) (...but probably wouldn't).
Failure at the creation attempt could mean anything from lost time to personal injury (caught in own half-finished trap) to utter ruin (destruction of workshop and sanity in the premature quest for the Philosopher's Stone).
I imagine this method could also be used for games based on resource-management or building; suppose you wanted to play a Risus-ified version of "Dwarf Fortress," an excellent resource-management game.
Individual dwarven crafters (small-scale) or the population at large (large-scale) could team up with a Resources cliche for the area (broken down by material, if desired), to create parts of a fortress (sturdy granite walls, devious traps, etc.).
Case 2 - Improvements and Additions
Sometimes, players might want to improve or add to an existing cliche.
Suppose a couple of characters are holed up in an Empty Bar (2).
They're expecting trouble, and would like to have a Walled-up Empty Bar (3). There are lots of things in the bar (benches, boxes, etc.) that could be used to block up doors and windows, so perhaps they could team up against the Empty Bar (2), and if successful, end up with the Walled-up Empty Bar (3). (It might now also have the cliche Ransacked(2), if the GM desires, to represent the lack of available benches, boxes, etc. for other purposes.)
This method could be used by a hurried Laid-Back College Student (4) trying to get a Messy Apartment (4) into shape for a romantic interest (at least knocking it down into Messy Apartment (2) by succeeding for a couple of time-consuming rounds before giving up - perhaps now with a reduced Laid-Back cliche for the purposes of being a charming host while exhausted), or by a Chef (4) attempting to improve the presentation of a Pretty-Nice-Looking-Meal (3).
For adding new cliches to existing objects (say, an Outer Wall(2) to a Fort(3)), maybe some combination of the above techniques could be used, rolling against the main cliche (Fort (3)) as well as (i.e. teamed-up with) the new cliche's power/difficulty (Outer Wall(2)) if the object might resist improvements. (The fort is already built, most of the convenient trees have already been cut down, etc.)
I'm sure there are many other approaches and possibilities for object and entity creation, but perhaps the above will provide a good jumping-off point to explore player-generated additions to the world.