Smithsonian Open Access contains millions of high-res public-domain images that are free to use:

https://www.si.edu/openaccess

A thread about playtesting videogames that also applies to tabletop games:

https://twitter.com/kchironis/status/1232720225700732928

Thoughts on what makes a game “playful”—deep and expressive but also low-stress:

http://keithburgun.net/achieving-playfulness-in-strategy-game-design/

“You want people to have a moment so exciting that they can’t wait to share it with their buddies.”

— Devin Low

What should be on your Kickstarter launch-day checklist:

https://medium.com/@fantastic.factories/what-should-be-on-your-kickstarter-launch-day-checklist-and-why-you-should-have-one-b95d15cc6e45

Principles for designing a game system that’s built to last:

https://level99games.tumblr.com/post/190810837571/designing-to-last-core-principles-in-game-design

Thoughts on some conventional wisdom for board game designers:

https://boardgamegeek.com/blogpost/98792/cutting-room-floor-episode-2-conventional-wisdom

The challenges of designing a game for a mass-market audience:

https://design100.org/53-mass-market/

“Is there a skill more important for a game designer to master than empathy? To be able to see when someone is confused or frustrated or excited without them telling you will keep you on the right path during design iterations.”

— Brian Henk

Designing games to make them more visually accessible:

http://www.weirdgiraffegames.com/carla/wordpress/2020/02/14/interview-with-sarah-reed-visually-accessible-games/

How a mismatch between theme and mechanics can mislead players—a Twitter board game design discussion:

https://twitter.com/Drawnonward/status/1228198679573495808

How the “payday effect” impacts Kickstarter campaigns depending on their launch day:

https://stonemaiergames.com/the-astounding-payday-effect-on-kickstarter/

A beginner’s glossary of board game genres:

https://www.dicebreaker.com/categories/board-game/how-to/board-game-types-explained

The benefits of working on multiple designs at once—and why your excuses not to aren’t any good:

https://subsurfacegames.ca/2020/02/11/multi-tasking-is-actually-the-best/

Are there any qualities that make a game objectively “good”? A Twitter board game designers discussion:

https://twitter.com/stuffByBez/status/1225751728743731200

“I don’t work on any contract that says “Payment upon publication.” NO ONE EVER SHOULD. I don’t care if you’re trying to break into the industry, I don’t care if you really, really trust the publisher. DON’T DO IT.”

— Kevin Wilson

“When we start making games we quickly realize that the game we made is NOT VERY GOOD! This is ok and this is normal. This is called experience. Unfortunately too many people stop trying around this stage because they feel like they are not good at it. Guess what? Neither was anyone at anything when they first started. It’s only through the experience of doing something that you get better at it.”

— Jay Cormier

How to avoid “overdesigning” your game so much that it becomes unplayable by newcomers:

https://subsurfacegames.ca/2020/02/06/sen-foong-lim-on-his-roadblock/

Three tricks for keeping backers engaged during the mid-campaign Kickstarter slump:

https://tabletopbackerparty.com/3-old-but-good-engagement-hacks/

Lessons from Quacks of Quedlinburg for aspiring board game designers:

https://brandonthegamedev.com/4-lessons-from-quacks-of-quedlinburg-for-aspiring-board-game-designers/