Mark Rosewater is a designer that makes the game Magic: The Gathering. When magic turned 20 years old he went to GDC to talk about mistakes that helped shape the most famoust and profitable card game in the world. He shared 20 lessons that Wizards learned over the course of 20 years. It's a card game but can the same principles be applied to level design?
Note: when Mark talks about players he's talking about an average. Not every player is the same and there is variance among the player base.
Part 1, part 2, part 3, Mistakes? I've made a few, Because salt makes mistakes taste great
In each of the lessons I can see how it's possible to relate what Mark Rosewater said to level design:
Lesson 1: Fighting against human nature is a losing battle
Lesson 2: Aesthetics matter
Lesson 3: Resonance is important
Lesson 4: Make use of piggybacking
Lesson 5: Don't confuse "interesting" with "fun"
Lesson 6: Understand what emotion your game is trying to evoke
Lesson 7: Allow the players the ability to make the game personal
Lesson 8: The details are where the players fall in love with your game
Lesson 9: Allow your players to have a sense of ownership
Lesson 10: Leave room for the player to explore
Lesson 11: If everyone likes your game but no one loves it, it will fail
Lesson 12: Don't design to prove you can do something
Lesson 13: Make the fun part also the correct strategy to win
Lesson 14: Don't be afraid to be blunt
Lesson 15: Design the component for its intended audience
Lesson 16: Be more afraid of boring your players than challenging them
Lesson 17: You don't have to change much to change everything
Lesson 18: Restrictions breed creativity
Lesson 19: Your audience is good at recognizing problems and bad at solving them
Lesson 20: All the lessons connect
Extra lesson 1: If your theme isn't common, it isn't your theme
Extra lesson 2: Every set is someone's first set
Extra lesson 3: Sometimes on the way to beautiful, you have a lot of chaos
Extra lesson 4: You have to be willing to question your absolutes
Extra lesson 5: Stop trying to make the thing everyone else wants you to make. Make the thing you want to make. You're at you're best when you're passionate about what you're doing. Find your passion
Extra lesson 6: The right answer is not always apparent at first
Design lesson 1: Look outside the box only after you've looked inside it (I changed the order in comparison to the original lessons. No particular reason, it's just that I didn't read and write in the same order as Mark)
Design lesson 2: If you can do without it, do without it
Design lesson 3: If it doesn't fit, don't force it
Design lesson 4: Listen to the uninvested
Design lesson 5: Nothing is set in stone
Design lesson 6: Everything affects everything
Design Lesson 7: Give yourself time
Design lesson 8: Mistakes are valuable
Design lesson 9: Don't fight human nature
Design lesson 10: Pay attention to feedback
Lessons by Sam Stoddard, one of the developers of Magic. For people unaware of the difference between design and development in regards to making Magic. Design is about concept. Development is about making that concept a real card, with tweaks to its concept to make it work in the game's environment. There is more than just that, but for now it suffices.
Top 8 lessons I've learned from leading a development team (Wayback machine archive. Sam has left Wotc in March 2019)
Development's lessons 1 and 2: Nothing beats good process | Iterate, Iterate, Iterate
Development's lessons 3 and 4: Math is more reliable than intuition | Don't try to fix everything at once
Development's lessons 5 and 6: Try the wrong way first | Change is good... and frightening
Development's lessons 7 and 8: Listen to dissenting voices | Making Magic sets is really hard