A Guide to Champion Classes For Beginners: Fighters
The following is an in-depth look at each Champion Class in League of Legends, and the intended role each one is meant to fill. This guide is the next in an attempted series to help inform new players of the roles of the game and the classes champions are classified in. Veteran players are also free to look at this guide and add their own comments/suggestions in the comments.
My first entry in this series dealt with Tanks. The link to that post can be found here:
FIGHTERS
We'll be looking at Fighters in this post. Fighters are described in the following way on the LOL Wiki:
"Fighters (also known as Bruisers) are a diverse group of short-ranged combatants who excel at both dealing and surviving damage. With easy access to heavy, continuous damage (or DPS) and a host of innate defenses, fighters thrive in extended fights as they seek out enemies to take down, but their limited range puts them at constant risk of being kept at bay (or kited) by their opponents via crowd control, range and mobility. Fighters tend to have an advantage against Assassins, whose burst tends to fall short of killing them when unaided, as well as Tanks, whose inferior damage allows Fighters to eventually defeat them in duels, but often struggle against Mages and Marksmen, whose superior reach allows them to kite approaching Fighters."
Fighters have 2 Subclasses: Divers, and Juggernauts.
Once again, from the LOL Wiki:
"Divers are the more mobile portion of the Fighter class. Divers excel at singling out high-priority targets to blitz toward, immediately forcing those targets (and their teammates) to deal with the diver’s presence. Divers are not as durable as the tanks or juggernauts of the world, but Divers can take their fair share of punishment while bringing enough damage to be a real kill threat if left unchecked."
"Juggernauts are melee titans who relentlessly march down the opposition and devastate those foolish enough to get within their grasp. They are the only subclass who excel at both dealing and taking significant amounts of damage, but in turn they have a tough time closing in on targets due to their low range and extremely limited mobility."
Fighters are intended to have an advantage against Assassins and Tanks. They are strong against Assassins because their innate defenses (Not as high as actual members of the Tank class but certainly nothing to be sneezed at) allows them to endure the burst an Assassin can bring (Usually 1 or 2 rotations, depending on the Fighter and their build versus the Assassin and their build). They are strong against Tanks because the Tanks overall lower damage output can't match what the Fighter brings to the table, and the fact that CC is supposed to keep people in fights, which is just what the Fighter already wants, to extend the trade/fight for as long as they can.
Fighters are disadvantaged against Mages and Marksmen, as the reach that these two classes have, both in the form of Spells and Auto-Attacks, tends to let them keep the Fighter at arms-length, or KITE, them. Aside from the effects of items like 
or 
and 
and the summoner spell 
, Fighters are less likely to be able to stick to them since the Mage or Marksman can just boot them away with their own CC or dodge the Fighter's own CC with their mobility, as the case may be with the champion themselves.
So first off, by looking at the description given to the class as a whole, we can see that Fighters are intended to both dish out, and take damage. While they have DPS, for the most part, they can't match what a Marksman can bring (Unless they are incredibly fed) and at the same time, can't reliably lock down opponents with constant CC like Tanks can. One could say the Fighter class is the "Jack-of-all-trades and master of none" of the classes of the game.
So, if a Fighter gets on a target, by this description, they are more than capable of killing them. It's just a matter of them GETTING INTO RANGE because of their limited range and/or mobility as the case may be with the champion/character themselves. So next time you're getting your face pounded in by a 
or an 
, it's because they were able to close the gap between you and them, and Fighters are at their most dangerous when they are in range.
Through one way or another, a way of describing Fighters is that they want to get in the thick of things, but unlike Tanks, who are in there for defense, the Fighters are there for Offense. They want to get in and FORCE the enemy to deal with THEIR presence first and foremost, thus allowing the other team-mates to hopefully take advantage of the distraction the Fighter is creating. If things go right, the Fighter CAN win the battle on their own, but, like with my Tank post, it means that the player needs to use their abilities, items and skill with their chosen Fighter champion wisely to make that CAN win scenario become a WILL win scenario.
Next we'll look at and try to elaborate on the descriptions of the two subclasses; Divers and Juggernauts.
Divers are opportunists, always looking for that opening that they can use to zoom in via their dashes/blinks or what-have-you and cause havoc, or like it says, "force the targets (and their teammates) to deal with the diver’s presence". So next time you see a 
or a 
or 
loitering about but not doing anything, it's because they're probably waiting for the opportune moment to strike.
Juggernauts, on the other hand, are usually of a different mindset. They'll just pick their target (or targets) and barrel down on them, taking hits all the while and more or less shrugging them off. If they can get in range, then you're in for a world of pain, because like it says above, "They are the only subclass who excel at both dealing and taking significant amounts of damage". So if someone like 
or 
or 
get on you, IT'S GOING TO HURT.
EXAMPLE SCENARIOS
Similarly to my other post of this nature, I'll give examples/hypothetical scenarios of what happens with the two classes that Fighters are intended to COUNTER. Namely, Assassins and Tanks.
is a Fighter, falling under the Diver subclass category.
is a Slayer, falling under the Assassin subclass category.
Unlike the other post, I'm not going to mention whether or not Irelia is listed as a counter specifically to Nocturne on any counter-picking websites. Let it suffice that her being a Fighter/Diver and he being a Slayer/Assassin should explain things, when compared to the above descriptions. Like the examples in my post on Tanks, assume that the Irelia and Nocturne are of roughly equal skill, levels, items, etc.
Let's say the Nocturne starts the fight by diving in on Irelia with his ult, hoping that the initial burst damage will give him an advantage. But Irelia uses her W's damage reduction to... well, reduce the damage. They start going at it in earnest, and things are pretty even for a bit. But Irelia then uses her ult, and via wise aim afflicts Nocturne with the disarming effect it has, preventing him from proccing his passive that had been keeping him in the fight. He attempts to retreat by using the Fear/CC his E grants, but it's not enough to keep her away because of the mark that Irelia's ult provided, allowing her to quickly close the gap once more with her Q, and a few more auto-attacks later and Nocturne is down for the count.
So like with the Tank post, here is a hypothetical example of a Fighter doing the above: killing the type of champion they are intended to counter. But, there's always the other side of the spectrum...
is a Fighter, falling under the Juggernaut subclass category.
is a Marksman (Marksman do not have any named subclasses at this point in time).
Equal levels, items, you know the drill.
Illaoi attempts to start the bout by using her Test of Spirit. But unfortunately, she misses Vayne, who used her Tumble Q to dodge the skillshot. Using her range advantage, Vayne is able to pelt Illaoi repeatedly with attacks while Illaoi attempts to bridge the distance with her MS Boost from her 
and the small dash her W grants and then Ulting to get some Tentacles to help. But Vayne uses her E, shoving Illaoi away and out of the viable range for her Ult's area of effect, and Vayne's own ult, combined with the invisibility granted by her Q while it is active and the boosted damage, combined with her W, quickly whittles down Illaoi and she is defeated.
So there is another hypothetical example, showing the vulnerability a Fighter has to the increased Range that a Marksman (Or a Mage, had I written one for them) have access to.
CONCLUSION
So, in IDEAL scenarios, Fighters should be considered opportunists, looking for some poor soul they can catch out and wail on with a barrage of powerful blows, and then use the adrenaline rush afforded from that victory to repeat the process with any other victim they can get their hands on.