Valve's "Secret Weapon"

Published 2023-05-24
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 -

Watch ad-free on Nebula -

=== Before you watch ===

Content warning: Blood, Combat

=== Sources ===

[1] Valve reflects on The Orange Box, ten years later | PC Gamer…

[2] Developer Commentary | Portal

[3] Portal Beta 2005 & More 2006 Content | Logan on YouTube
   • Portal Beta 2005 ...  

[4] Beyond the Box | 1UP

[5] Kim Swift - 'Our Journey From Narbacular Drop To Portal' | IGS 2007
   • IGS 2007: Kim Swi...  

[6] Narbacular Drop | Digipen Institute of Technology…

[7] Valve's Design Process for Creating Half-Life 2 | GDC 2006…

YouTube mirror:    • Valve's Design Pr...  

[8] Valve’s philosophy with User Research... | Steve Bromley…

[9] The Science of Playtesting | GameSpot…

[10] Opening the Valve | Eurogamer

[11] Valve Is Finally Ready to Talk About Its Games Again... | The Escapist…

[12] Thinking With Portals | Game Developer Magazine

[13] 126 - Josh Weier Interview | Kiwi Talkz…

[14] The Cabal: Valve's Design Process For Creating Half-Life | Game Developer Magazine

[15] Handbook For New Employees | Valve

[16] The 100 greatest video games of all time... | GQ…

[17] The Final Hours Of Half-Life 2 | Gamespot…

[18] Why Are Valve's Games So Polished? | IGN…

[19] Half-Life 2: Episode One Update Released | Steam

[20] How fidgeting playtesters convinced Valve... | PC Gamer…

[21] Christine Phelan - Creating a Nightmare... | Konsoll 2021
   • Konsoll 2021: Chr...  

[22] Integrating Narrative into Game Design... | GDC 2008
   • Integrating Narra...  

[23] RPS Interview: Portal's Kim Swift... | Rock Paper Shotgun…

[24] Meet the minds behind Half-Life 2 | PC Gamer

[25] The Final Hours of Portal 2 | Steam…

=== 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 - (Referral Link)

Narbacular Drop - Full Walkthrough | COG in the Game
   • Narbacular Drop -...  

Konsoll 2021: Christine Phelan - Creating a Nightmare in Half-Life: Alyx | Konsoll
   • Konsoll 2021: Chr...  

F-Stop (After-Image) - "lab_intro_scripted2" | fstop
   • F-Stop (After-Ima...  

Portal 2: F-STOP PROJECT CAPTURE - Full Walkthrough | Bolloxed
   • Portal 2: F-STOP ...  

Exposure by LunchHouse Software | LunchHouse Software
   • Video  


=== Subtitles ===

Contribute translated subtitles -

All Comments (21)
  • MaarP
    Imagine the anxiety when gabe stopped the presentation, then the whiplash when they all got jobs at valve, an absolute dream
  • Deborn
    Kind of funny how Portal, a game all about testing and test chambers, would never have been as succesful as it was without its extreme amounts of player testing.
  • Ivy in my Heart
    This type of development requires a very special style of leadership that doesn't punish their employees when they get negative feedback. If tests are done every week, and every week you hear what doesn't work with your current approach, your boss needs to be fully behind you to consider it a chance for improvement and not a "trick" to point out all of your mistakes.
  • Action
    This “antagonist” concept is exactly why a lot of portal-inspired first person puzzle games fall flat and feel lifeless.
  • Louis Nemzer
    I have huge respect for the level designers of Portal
  • Dazcar
    my new headcanon is that the "science" done in portal is just in-universe playtesting
  • Ben Moody
    These Valve guys are pretty good, maybe they should make some more games
  • Novae
    14:03 This is especially shown in the climax of Portal 2.

    Realistically, "shoot the moon" is the easiest puzzle solution of all time. It's basically the only interactive option on the screen. But seeing everything fall apart around you, tension at the highest point, and calling back to the source of portal surfaces; that made the climax incredibly satisfying without being hard.
  • GreyWolfLeaderTW
    One of the best playtesting stories out there is when Shigeru Miyamoto's son first picked up and played Super Mario 64. Miyamoto was a little concerned with the fact that he wasn't showing interest in going into the paintings of Peach's Castle to go after the power stars, but spent over half an hour just running around and jumping and trying to run up and slide down slopes, walls, and attempt wall kick jumps outside Peach's Castle.
    It ironically was a good sign, because as his son and so many other children pointed out in the post-playtest interviews for Super Mario 64, they LOVED how well Mario controlled. Miyamoto and his team spending a year focusing on Mario's controls, statistics, and animations really paid off if the simple act of running and jumping around in a 3D game could be fun.
  • Crep50
    My brother actually found out “players never look up” the hard way - as a player. There’s a temple in Twilight Princess where one of the last puzzles is simply looking up - super easy in hindsight, but it took him over an hour to solve it.
  • I saw an article about one of the artists behind one of L4D2's cover arts a while back, and Valve seems to have a very intense method of assuring the quality of their game's elements. The artist had a few gripes with the cover art, and apparently Gabe Newell took it upon himself to have a one-on-one conversation inquiring why the artist felt the cover art was a bit off, and if he could articulate his issues with the image in a clear, concise manner. Creative work indeed has a very arbitrary scale of whether it's good or bad, and something tells me Valve's work culture plays a huge part in fostering/shaping that creativity into meticulously crafted ideas that have played a huge role in shaping the gaming landscape as we it is today.
  • Ghost_Puppy
    Pretty fitting that the developers of Portal also loves testing ;)

    Seems like Valve realized this too since they love using Portal to showcase their new tech like VR and the Steam Deck.

    It's basically their mascot nowadays
  • olppa1
    When Valve was busy developing CS2 which is coming out soon, they invited bunch of community figures and ex-pros to playtest it at Valve HQ. These people later said that there were dozens of Valve employees watching them play live in the same room. And all the time they were asked feedback and sometimes changes based on that were implemented the same day. This video gave me some background to that story.
  • Dexter Grif
    Valve’s developer commentary is fascinating. Hearing about how they changed the puzzles to make it so players didn’t get stuck but also not easy enough for it to be a cake-walk (pun not intended) is really cool and gives a lot of insight into what it’s like to develop a game.

    If only they still developed games.
  • Wolfcl0ck
    For most of the first year of Portal's development, the "actual game" was the tutorial. The final game's sequence of test chambers were all initially concepted as being the tutorial section for a much larger game that they scaled back on significantly.
  • ItsBossTime
    I've been watching your videos for years and this might be your best work imo. You don't just "still have it", you have improved like crazy. Genuenly thank you for making videos like this.
  • This game has the most adorable sentry guns ever made.
    It's actually kinda mad when that sentence makes people go: yes, yes indeed. You're absolutely right.

    Who on earth decided to make sentry guns of all things, cute and lovable? And make you feel sorry when taking them out?
    I fear Gabe adds something fishy to the office coffee maker every morning 😆
  • BocataDeClavos
    We'll never stop talking about Portal, and that's beautiful. What a masterpiece.