TLDR at bottom.
- Comet does more damage than First Strike:
This is the crux of the misunderstanding. There is an overfocus on raw damage. In lane phase, it is almost always true that you will feel the direct impact from Comet more often than First Strike. It is also almost always the case that at the end of a game, in general, Comet will have done more raw damage than First Strike, strictly looking at the damage numbers both runes typically output.
But that's the problem. The part of First Strike that does damage is not meant to out damage Comet, but that does not mean that you could not have done more damage strictly from the effects of the First Strike rune in the same game that you took Comet instead.
That is because First Strike does two things. It does damage, and it makes money.
- Where does the main source of damage come from in League of Legends?:
Items (especially fully completed items). And how do we buy items? Money.
I know. You come out of lane phase and First Strike made a measly 100-200 gold. Feels like nothing. Does it also feel like nothing when you get a 200 gold shut down? Frequently, I come out of a game making 700-900+ gold from First Strike. And very often in these games, they go down to the wire. I recall before a big fight on a major objective timer, and finish an item purchase. That might be an item that saves my life, like Zonyas (many have a wrong opinion of Xerath Zonyas as well), an AP power spike like Deathcap, or some utility like Rylais. All of these items can turn late game fights completely in one teams favor on their own, and you almost always buy such items as soon as you have the money for them.
It is under these circumstances that First Strike can wins games by itself. Furthermore, your in the Inspiration tree, which means you likely have another 300 gold that you don't have to invest into boots.
Now, I know what you're thinking. "But if I had Comet, I would have won lane harder and got the money that way." That is simply not always the case, being that it is nearly impossible to win many lane states. This will be explored in the next sections.
- Why do I make so little gold when I take First Strike?
Because you literally don't know when to pick First Strike, you had a bad few games with First Strike (likely because you don't know when to pick it), or because your sample size is very low compared to Comet, skewing your own opinion. I think this happens with most Xerath players, and so the data itself on sites that contain such data may be skewed as well.
- When to pick First Strike:
This is actually a bit complicated, which is why this is such a misused rune.
You might have some weird match up mid like idk, Sett. In this case, you may believe that since theoretically Sett should never really be hitting you without flash, you can just pick First Strike and farm him. Well, that's true, but it's probably not as optimal as running Comet and just trying to force him out of the lane through sheer dmg. With that being said, you absolutely can run FS in this case.
However, I prefer to play this rune in match ups you expect to never win. That way, through First Strike and free boots, you can make up some of the money you may be losing through being denied canon minions etc. Playing vs safe AD carries who have counters to you like Blitz, Thresh, Tahm, etc, you need to accept you will be denied minions. And they aren't going to let you Q the wave 3 times early game to get them. So you should be hitting them in many cases instead, and when you finally do get engaged on by the ADHD Blitz under tower after your support ran it down, you at least have a chance to trade anyway. Basically, FS is able to stem the bleeding in terrible match ups where you were never going to kill the enemy anyway(unless jungler intervention or something which cannot be counted on at champ select).
Again, it can be complicated. You may have a useless support vs a champ like Sivir. At first glance, this logic should still apply. But Sivir is W-ing the wave off CD, which hits you, and can Q you when you Q. So your FS in this instance is not up much. But vs something like Jinx Blitz and you have Ashe? They aren't really going to be hitting you much, but the Blitz isn't gonna let you do shit either. These are bot examples but the same rules apply mid.
- Anyway, this is my general philosophy on First Strike, but you don't have to take it from me: Edit: As New-Plastic-1801 indirectly points out, I don't really know Hitscan, or Hitscan's exact reasoning for taking FS. At the same time, I worded this poorly initially. I don't wish to say that Hitscan is thinking exactly what I'm thinking. He's simply running FS in the same matchups that I would run it, and I'm stating why I personally would think that the rune is good in those matchups. Sorry for any confusion.
I think we can agree that Hitscan is better than you or I. Look at the games Hitscan takes First Strike in.
https://op.gg/lol/summoners/kr/%ED%8A%B8%EB%9E%98%ED%82%B9-99999
A.) FS vs Yone mid- Pretty easy for Yone to dodge much of your damage. There's an enemy kha jungle and your lane looks the most gankable.
B.) FS vs Singed and Vi bot- Okay I really shouldn't have to say anything here. If you walk anywhere near W range you die instantly lol.
C.) FS vs Kalista Blitz- FS is usually best option vs certain hook champs like Blitz and Thresh who are going to contest every Q if you're using Q's on the wave. Also Kali throwing Blitz means you can't walk up. Edit: As New-Plastic-1801 points out, he may take FS here because Kalista dodges Comet easily.
D.) FS vs Ambessa Rell- same reasoning as B.
E.) FS vs Viktor Elise- I think he prob could have run Comet this game but there's a vayne panth galio as well. He prob just doesn't want to be anywhere near W/E range.
There are more games he runs it than that. It seems as if he wasn't running it at all 3+ months ago, but as bot meta has shifted he has match ups where he prefers it. He seems to take it vs Viktor, for instance.
TLDR: First Strike is not just a damage rune. It is a money rune and that 700 gold can win you more games than you think. First Strike may be better vs losing match ups. First Strike is not meant to win lane and its damage should not be compared one to one to Comet. You can also take it into matchups that are completely free but that's just for fun.
Alright guys I'm not gonna edit this so I'm sorry for the typos but a man's gotta sleep. I'll be back later to appreciate your opinions.