Valve is famous for crafting games that are polished and intuitive. But that's no accident: the developer has a near-religious obsession with playtesting. Learn more, in this video.

Support GMTK on Patreon - https://www.patreon.com/GameMakersToolkit

Watch ad-free on Nebula - https://nebula.tv/videos/gmtk-valves-secret-weapon

=== Before you watch ===

Content warning: Blood, Combat

=== Sources ===

[1] Valve reflects on The Orange Box, ten years later | PC Gamer
https://www.pcgamer.com/valve-reflects-on-the-orange-box-ten-years-later/

[2] Developer Commentary | Portal
https://store.steampowered.com/app/400/Portal/

[3] Portal Beta 2005 & More 2006 Content | Logan on YouTube
https://www.youtube.com/watch?v=Uo7sozG32F0

[4] Beyond the Box | 1UP
Archive: https://web.archive.org/web/20110524000033/http://www.1up.com/features/beyond-the-box

[5] Kim Swift - 'Our Journey From Narbacular Drop To Portal' | IGS 2007
https://www.youtube.com/watch?v=2F0SVZA9fIo

[6] Narbacular Drop | Digipen Institute of Technology
https://www.digipen.edu/showcase/student-games/narbacular-drop

[7] Valve's Design Process for Creating Half-Life 2 | GDC 2006
https://www.gdcvault.com/play/1013237/Valve-s-Design-Process-for

YouTube mirror: https://www.youtube.com/watch?v=1plhILdjuZE

[8] Valve’s philosophy with User Research... | Steve Bromley
https://www.stevebromley.com/blog/2011/09/01/valves-philosophy-with-user-research-in-games-habe-newell-and-mike-ambinder/

[9] The Science of Playtesting | GameSpot
https://www.gamespot.com/articles/the-science-of-playtesting/1100-6323661/

[10] Opening the Valve | Eurogamer
https://www.eurogamer.net/i-valve-060606

[11] Valve Is Finally Ready to Talk About Its Games Again... | The Escapist
https://www.escapistmagazine.com/valve-ready-to-talk-about-its-games-again-nine-years-later/

[12] Thinking With Portals | Game Developer Magazine
[PDF] https://ubm-twvideo01.s3.amazonaws.com/o1/vault/GD_Mag_Archives/GDM_January_2008.pdf

[13] 126 - Josh Weier Interview | Kiwi Talkz
https://www.listennotes.com/podcasts/kiwi-talkz/126-josh-weier-interview-hRrUGebZ1w9/

[14] The Cabal: Valve's Design Process For Creating Half-Life | Game Developer Magazine
Mirror: https://www.hl-inside.ru/magazines/gdm/GDM_1999-12/

[15] Handbook For New Employees | Valve
[PDF] https://cdn.akamai.steamstatic.com/apps/valve/Valve_NewEmployeeHandbook.pdf

[16] The 100 greatest video games of all time... | GQ
https://www.gq-magazine.co.uk/article/best-video-games-all-time

[17] The Final Hours Of Half-Life 2 | Gamespot
https://www.gamespot.com/articles/the-final-hours-of-half-life-2/1100-6112889/

[18] Why Are Valve's Games So Polished? | IGN
https://www.ign.com/articles/2009/03/27/gdc-09-why-are-valves-games-so-polished

[19] Half-Life 2: Episode One Update Released | Steam
https://store.steampowered.com/oldnews/681

[20] How fidgeting playtesters convinced Valve... | PC Gamer
https://www.pcgamer.com/how-fidgeting-playtesters-convinced-valve-to-drastically-shorten-half-life-alyxs-intro/

[21] Christine Phelan - Creating a Nightmare... | Konsoll 2021
https://www.youtube.com/watch?v=Wf92MhRZ4i8

[22] Integrating Narrative into Game Design: A Portal Post-Mortem | GDC 2008
https://www.youtube.com/watch?v=c2YRVWZupwo

[23] RPS Interview: Portal's Kim Swift and Jeep Barnett | Rock Paper Shotgun
https://www.rockpapershotgun.com/rps-interview-portals-kim-swift-and-jeep-barnett

[24] Meet the minds behind Half-Life 2 | PC Gamer
https://www.pcgamer.com/meet-the-minds-behind-half-life-2/

[25] The Final Hours of Portal 2 | Steam
https://store.steampowered.com/app/104600/Portal_2__The_Final_Hours/

=== Chapters ===

00:00 - Intro
01:25 - Playtesting Portal
05:47 - Valve's History
08:38 - Playtesting Tips
15:43 - Conclusion

=== Games Shown ===

Portal (2017)
Super Mario Odyssey (2017)
Far Cry 3 (2012)
Ratchet & Clank: Rift Apart (2021)
Portal 2 (2011)
Star Wars Jedi: Survivor (2023)
Narbacular Drop (2005)
Half-Life 2 (2004)
skate. (Unreleased)
Left 4 Dead (2008)
Half-Life 2: Episode One (2006)
Half-Life Alyx (2020)
God of War Ragnarök (2022)
Untitled Magnet Game (Unreleased)
Superliminal (2019)
Viewfinder (Unreleased)

=== Credits ===

Music provided by Epidemic Sound - https://www.epidemicsound.com/referral/vtdu5y (Referral Link)

Narbacular Drop - Full Walkthrough | COG in the Game
https://www.youtube.com/watch?v=tZO3KvTcATo

Konsoll 2021: Christine Phelan - Creating a Nightmare in Half-Life: Alyx | Konsoll
https://www.youtube.com/watch?v=Wf92MhRZ4i8

F-Stop (After-Image) - "lab_intro_scripted2" | fstop
https://www.youtube.com/watch?v=-Y3lFdqtO-Y

Portal 2: F-STOP PROJECT CAPTURE - Full Walkthrough | Bolloxed
https://www.youtube.com/watch?v=NM5oxIbL4ds

Exposure by LunchHouse Software | LunchHouse Software
https://www.youtube.com/watch?v=x9vUzt9xhnI

Mirror: https://www.playground.ru/portal/news/anons_exposure_serii_dokumentalok_ob_otmenyonnom_prikvele_portal-704827

=== Subtitles ===

Contribute translated subtitles - TBA