Some design decisions that can help make sure players have fun even when they’re losing:
Various ways of sparking inspiration for a board game design:
http://www.weirdgiraffegames.com/carla/wordpress/2021/02/08/ways-to-spark-inspiration/
What to know about approaching publishers as a first-time designer—a BoardGameGeek designers forum discussion:
https://boardgamegeek.com/thread/2583408/do-publishers-trust-new-designers
