There are several ways to get extra turns in a game: Seize the Day, Outpost, Mission, Fleet...not to mention the evil and banished Possession. (And maybe others that I'm not thinking of right now.). Fine so far. And, on the the game log, when you get an extra turn, the log shows it as two consecutive (for example) Turn 6. I just tested this out, with Outpost and Seize the Day (#4306 5673, Turns 2 and 6, for example).
Again, fine so far. I can see coding reasons why you'd want to keep turn numbers even between opponents. Probably Turn 6a and 6b would have been more clear, but two 'Turn 6' is clear enough. And it would be a very confusing game log if your Turn 6 happened right after my Turn 9.
BUT, at the end of a game, I think the computer just looks at the recognized number of turns and, if you're both showing 21 turns, then it calls the game a tie. But this is not correct, according to the rules, which state that, in the event of a tie, the one with fewer turns (if applicable) is the winner. I see nothing in any rule that says, "We will count "regular" turns but none of the extra turns, in calculating if players have the same number of turns in tie games."
Did I miss something in the rules? (Sadly, when I've bought crappy "extra turn" cards/events to test it out; I've been unable to end up in a tie game with equal "regular" turns.) So, sorry in advance if the game actually *does* add in those extra turns at the end of the game. For my IRL games, we've had to just write down each time a player used Outpost (et al), and kept a running track, in case of a tie. There's also been some debate about IRL games, if that running total of extra turns info must be shared with other players, or, if it's just good manners to do so.