Yeah, I've had tournaments where the difference between 1st place and 4th place is differential, so it's important to calculate.
The Organized Play Guide
explains the (byzantine) rules for calculating differential. Not only do you have to deal with cards like New Civilizations, you also have to deal with:
* Games where one or both players never solved a mission, and so their bonus points don't count.
* Games where one player finished in negative points.
The OPG rounds this up to 0 points for calculation of differential... so, if the actual score of a game when time expires is Player A has -4 and Player B has -15, I believe it will be reported as "MW Player A 0-0 (+0)".
* Games where, due to "must have an additional 40 points to win" effects, a player scored over
100 points and won... or even where a player scores over 100 points and loses
. (Happens to my Delta decks a lot!) Anyone with >100 points who wins is reported as scoring 100 points. Anyone with >100 points who loses is reported as scoring 99 points. So if I lose to you that way, it'll be reported as "FW Ensign Q 100-99 (+1)."
All this is outside my department of 1E rules, because it's just organized play stuff that doesn't actually affect the game (just tournament pairing and player ratings), so I'm absolutely not a master of it, but it's fascinating stuff all the same.
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