“Use whatever tools you can to get to a first playable ASAP - scrap paper, rules in Notepad, scribbled diagrams etc. then play it out yourself or with someone ASAP even if (especially if) you realize it’s crap within 5 minutes and have to redo everything.”
Wargame designer Hermann Luttmann offers advice for new designers:
https://www.diagonalmove.com/so-you-want-to-design-a-board-game/
Hermann Luttmann, designer of Dawn of the Zeds and At Any Cost, on designing wargames and historical-simulation games, working on solo games, small-scale vs. large-scale games, and more:
https://www.diagonalmove.com/interview-hermann-luttmann-designer-of-dawn-of-the-zeds-at-any-cost/
“If it stops being fun and feels like a chore, take a break. Come back to it when you’re feeling it again. When you play a game, you can feel how much fun the designer had making it, so ensure that you maintain your own passion for what you love throughout the process, and most of all enjoy yourself, so you know that your players will, too.”
Daily exercises to get your next game design session off to a creative start:
https://docs.google.com/spreadsheets/d/1EL8_UgBh4VnNFJh6Fa8cnVVqxKtWEKbnTF7IAIN9cZI/edit#gid=0
Board game designers share their favorite prototyping tools:
https://twitter.com/ProtospielNotts/status/1273293939924230150
Tips for designing your games for a specific audience (audio):
https://www.boardgamedesignlab.com/designing-games-for-a-specific-audience-with-phalgun-polepalli/
Lots of pointers for running a smoother online playtest:
http://www.thegamespeople.co.uk/getting-the-most-from-virtual-playtesting/
A thorough survival guide to pitching your game, from scheduling and preparing to answering questions and tracking your progress:
https://www.dmrcreativegroup.com/post/pitching-survival-guide
A note on the “rules” for new designers to follow—but also when to break them:
https://twitter.com/KevinWilson42/status/1270757552834347011
Making your prototype more appealing for pitches through stock art, example diagrams, decent components, and a how-to-play video:
https://randomskill.games/so-you-think-you-can-be-a-board-game-designer-part-5-presentation/
