Probably the most interesting definition of combat rounds I've seen. From The Marvel Super-Heroes Basic Set.
'Turns are not a precise measurement, they take about five to 15 seconds each, which roughly translates into one panel of a comic book. Your character can perform in one round whatever can comfortably fit into a single panel of a comic book. That's why heroes can deliver a long speech and clobber the Red Skull in a single turn, but only the fastest of them can take multiple actions in the same turn.'
I've noticed in playing D&D and story games that the exact division of time during rapid actions, especially when player opposes player, has a huge effect on the nature of play. Time must be both exact, (because at the momemnt to moment transaction, time is a diminishing resource) and also flexible, in order to allow the narritive power that helps charge events with meaning.
If time is measured too ferociously, events become very closely described in the game, both by the players and as a general consequence of play. This granularity seems sometimes to rob actions of wider meaning. If time becomes too 'fluffy' or soft, then tension is lost and meaningful decisions become harder.
Generally speaking, during a game, the closer you measure time the more Hobbsian and conservative it gets. People play to safeguard and horde whatever they have, both as characters in the game and as players. They play to limit negative results. They can also get much more creative with the things they do have. When you go the other way, things become more relaxed, players improvise, invent differently and add energy to the game in a different way, usually by connecting things over a wider context.
These are both good things and lend emotional and intellectual counterpoint to the game.
(I am not just talking about having losts of small, little, sharply defined events vs a few large fuzzy events but about the level of mixing between the two.)
The decription above of time as a meaningful, but limited dramatic unit is one I will keep in mind when I play next. It also makes immediate intuitive sense.
(But I suppose only really makes sense if you think about is as superhero comics from the 50's to 80's though. Any other kind of comic or even comics from a different period might produce something quite different.)
If I ever get round to statting up the Hours for Balach, I will probably have them each have a differrent approach towards narritive time. Like one has turns like comic panels, another has turns like lines of poetry, another has turns like cuts from a film, another has turns like memories e.t.c. So you will know what time it is in Balach by how time is decribed in the game.
i.e 'Hmm, we're moving from clear moment to clear moment with a straight 4th edition division of Standard, Move and Minor actions per turn. It must be three O'Clock. Should I get this battle done before it turns Four O'Clock, or extend it so we can kill the orcs while counting time as moving from decison to decision rather than second to second?'