Area control: what the mechanism is, games that have used it, and the experience it offers for players (video):

https://www.youtube.com/watch?v=Bp-WWRF8Y7I

The ABCs of board game design (A-F): quick explanations for common terms used by board game designers (video):

https://www.youtube.com/watch?v=YV1JffFIaO0

Rulebook writing fundamentals: What rulebooks need to achieve and basic concepts for making sure they do (video):

https://www.youtube.com/watch?v=rhOeHsEu3n4

When higher numbers aren’t necessarily better: examples of games where both high and low numbers can be useful depending on the situation (video):

https://www.youtube.com/watch?v=f6TL34Y1zYk

How giving players choices helps them feel engaged in the game’s outcome (video):

https://www.youtube.com/watch?v=3MipF7EGrls