Why engage the enemy when you can just avoid them? Dodging blows is a classic strategy in real combats.
However it's not always possible to specify a dodge manoeuvre in response to an attack in some games. The venerable Dungeons & Dragons has no such dodge mechanic at all. The 5th Edition rules have a combat action named "Dodge" (and the 3rd Edition rules have a similar feat), but this isn't the same thing - it's really a precautionary defensive tactic to forgo attacking and jump around a lot and make yourself generally harder to hit, which provides a penalty to the attacker's attack roll rather than being a response to a specific incoming blow. Not that this is necessarily a bad thing - a game doesn't necessarily need a Dodge mechanic.
Some games (e.g. GURPS) do have an explicit Dodge mechanic, that can be declared in response to any incoming blow. The cost of this extra simulated realism is adding some complexity to combat. So it really depends what you're going for in your game style.
Commentary by memnarch (who has not seen the movie)
Wow Luke's got some moves. Especially for being an old guy! This is a lot more exciting a lightsaber fight than I was expecting from the stance Luke had.
Thinking about it a bit, Luke doesn't actually need to get a quick win here either. If the goal is to delay Kylo and the First Order from getting into the base, dodging around and pissing Kylo off are perfect tactics to use. It's just a nice side effect that we're getting what's one of the more unique Star Wars fights to date.
Also? I just want to take a moment to appreciate the Irregulars in picking out that specific frame for panel 5 to make Kylo even more goofy looking. I already think he's a doofus (possibly erroneously) so more evidence there is always nice.
Transcript
Kylo Ren: Raaahh! {charges at Luke}
[SFX]: Whooom!
[SFX]: Whooom! {Kylo swings at Luke}
[SFX]: Dodge! {Luke dodges the blow}
[SFX]: whmmm... {Luke stands holding his sword}
Kylo Ren: Wait. Rey gave the sword back to you?
[SFX]: whmmm...
Luke: I used it before. And Anakin before me. You know. The nine-year-old kid who almost killed you.
Kylo Ren: I’ll destroy you! And your stupid sword!
[SFX]: whmmm...
[SFX]: Whooom!
Kylo Ren: Raaahh! {charges at Luke again}
[SFX]: Whooom! {Kylo swings at Luke}
[SFX]: whmmm...
[SFX]: Dodge! {Luke dodges the blow again}
[SFX]: w h h o o o o m ! {Kylo’s sword swings in slow motion millimetres above Luke’S face as he bends over backwards to dodge it}
[SFX]: l a s e r s w o r d t i m e {Luke’s reflexes are so fast it makes the sword motion seem super slow}
[SFX]: Whooom! {Kylo swings at Luke}
[SFX]: whmmm...
[SFX]: Dodge! {Luke dodges the blow yet again}
Luke: The Jedi doesn’t choose the sword. The sword chooses the Jedi.
[SFX]: whmmm...
[SFX]: whmmm...
Kylo Ren: Maybe it should choose a Jedi who actually uses it!
Luke: Maybe if you didn’t keep making air swings I’d have to.