Soul-of-the-Work Filter
Keep only features that strengthen the product's defining experience
- Difficulty
- Moderate
- Time to result
- ~weeks to results
- Steps
- 5
- Confidence
- 99%
Build enough of the intended product to experience it, then identify the quality that gives it life and use that as a filter for every feature. Romero describes bringing stealth mechanics from Castle Wolfenstein into Wolfenstein 3D, including dragging and searching bodies. Once implemented, those mechanics interrupted the new game's defining strength: unprecedented high-speed movement and run-and-gun action. The team removed completed work that slowed that experience, despite its fit with the source material. The filter is not a simplistic demand for speed or minimalism. Doors remained because waiting for them created suspense, which supported the experience rather than merely delaying it. The mechanism is continuous coherence testing: observe the emerging product, name its soul, and keep, alter, or remove elements according to whether they reinforce it.
Origin
Extracted from The Tim Ferriss Show through John Romero's account of refining Wolfenstein 3D around speed and suspense.
Core principles
- 01The product's real strength can emerge during use
- 02A good inherited idea can be wrong for a new context
- 03Completed work is not protected from removal
- 04Necessary friction can strengthen the core experience
How to run it
- 1
Experience the working product
Use the product in its current form rather than judging only from the original specification. Notice where it feels most distinctive and engaging.
Pro tip Evaluate the experience in motion, where interactions between features become visible.
- 2
Name its soul
Express the product's defining strength in a short, specific phrase. For Wolfenstein 3D, Romero identified high-speed run-and-gun play.
Pro tip Name a felt user experience, not a market category.
Watch out A broad label cannot discriminate between features.
- 3
Test each feature
Ask whether each element reinforces, interrupts, or has no effect on the defining experience. Include features already completed and ideas inherited from successful predecessors.
Watch out Past investment and source fidelity can disguise a poor fit.
- 4
Remove contradictions
Delete or redesign elements that pull users away from the product's strength. Treat discarded implementation as the cost of discovering the right product.
- 5
Preserve purposeful tension
Keep friction when it creates suspense, pacing, or another effect essential to the soul. Distinguish meaningful tension from accidental interruption.
Pro tip Explain the emotional job of every retained pause or obstacle.
In the wild
id Software implemented body dragging and searching from Castle Wolfenstein in Wolfenstein 3D. Playing the new game showed that stopping for those actions contradicted its emerging high-speed identity, so the team removed them while retaining doors that created useful suspense.
→ The design concentrated on fluid run-and-gun action without eliminating suspense.
Common mistakes
Protecting sunk work
A programmed feature still damages the product when it contradicts the defining experience.
Copying the predecessor literally
A mechanic that fit the original context may oppose the strengths of a new format or technology.
Removing all friction
Some pauses create suspense or pacing and therefore reinforce rather than weaken the product's soul.
Is it for you?
Best for
It is best for working products whose defining user experience has become visible through real use.
Not ideal for
It is not ideal before there is enough of a product to experience and compare.
From the transcript
“The soul of this game is high speed, run and gun. Anything that stops you needs to come out.”
“So even though we programmed in that stuff, we pulled it out because it wasn't true to the new spirit of the game, the one…”
“But there were some things that we had to leave in, like to open a door and wait for the door to open, that's actually…”
From the episode
#681: Doom Legend John Romero — The Path to Prolific Innovation and Making 130+ Games, How to Find the Soul of the Work, Audacious Ambition, and Building in Monk Mode
John Romero