Even in the distant future, out among the stars in the furthest reaches of space, mankind is a pretty bloodthirsty bunch.
At least, that's what sci-fi movies would have us believe. And, given our track record as a species, it's probably a safe assumption.
As a result, sci-fi and action are genres that often go hand in hand. Whether we're talking about more grounded, near-future sci-fi or something a little further afield, mankind - or other species that look remarkably similar - always finds a way to start some sort of war.
With the added scope of other planets, other life forms, and advanced technology, sci-fi is able to offer some of the largest, most incredible battles ever committed to film. There's something special about being shown what tomorrow's horrors of war might look like, even if it is borne from a particularly morbid, depressing type of curiosity.
What constitutes a great battle is a little tricky to nail down; in some instances it's sheer scope, in others it's all about the implications, and, in a select few, it even comes down to choreography.
So sit back, relax, and hope your descendants aren't caught up in anything like the following ten greatest battles in sci-fi movie history.