When I finally sat down to play XCOM: Enemy Unknown (a franchise completely new to me, in a genre I don't dabble in very often), I was offered a pair of options upon starting a new game. The first was the difficulty, and I chose Normal, this later turning out to be a mistake because I suck somewhat at strategy games. The second was “Ironman” mode.
Ironman, for those of you who haven't played XCOM before, is a game mode in which you are assigned a single save slot to record your progress, with no control over when it saves. This essentially means that you are permanently tied to every single decision you make in the game, and cannot simply "re-do" that fourth mission because the soldier you named after Mary from work died to an alien's beam weapon. No backsies.
What struck me as odd about this option was that a lot of the XCOM players on my Twitter feed would turn it on when playing through the game for the second time, rather than the first. It was something I chose without hesitation on my first play, though, and this is primarily for one reason: In any game, I believe all my choices should be permanent, by default. Because when they are, it starts to feel like my interaction with games matters.