Because the subject of this post is over 9000 words long, I'm only including a link to its Web location (PDF or HTM).
This is a game glossary, but unusual in two respects: it includes both tabletop games and video games, and it is a glossary for game designers, not for game players. It has been written for inclusion in a book about game design.
What I am looking for from BGDF is suggestions for entries that should be there but aren't, ones that are there but shouldn't be, and ways that the existing entries might be improved.
Links:
PDF: http://pulsiphergames.com/glossaryforgamedesigners.pdf
HTML: http://pulsiphergames.com/glossaryforgamedesigners.htm
Sorry, I'd have sworn I tested those links.
Diplomacy is a non-trivial zero-sum game, practically speaking. Yes, it applies only to parts (in this case, the way you gain and lose units). In games with units, the gaining and losing units part tends to be most important.