Playtest is the structured process of trying a design out — typically a game, but increasingly a product, service, or experience — to surface bugs, flaws, and friction points before committing it to a wider release.
The term originated in computer, board, and role-playing game development, where playtesting is an established part of quality control: rules get tightened, mechanics get balanced, and edge cases get caught while the cost of change is still low. The same move has since carried into product design (closed beta, dogfood, internal alpha), service design (pilots, walk-throughs), and into 📝Lifestyle Design, where the unit being tested is the life being chosen rather than the artifact being shipped.
The term was introduced to me by 📝Wil Schroter, who applied it to lifestyle design directly — while house-shopping with his wife, he suggested, "let's move into the place we wanted to retire to see if we hate it." By arranging the experience of the outcome at the onset, they made the case for the means required to get there.