Aythreuk

RNG for those who don't know means random number generation, aka luck and I'm going to explain to you why for the most part it SUCKS.

The more RNG plays a part in a videogame, the less the player is able to make intelligent and calculated decisions. I think this shows clearly in a comparison between Company of Heroes and Starcraft.
I wasn't the one to pick this comparison either, I credit this to a fan of Company of Heroes who had this to say about the game's randomness

A_CoH_player wrote: This isn't StarCraft, units don't just stand in a line and Damage Per
Second each other to death. This game simulates battle situations in
a more realistic way than your traditional RTS, hence the random
occurencies which could happen in real life

Multiple things about this comment annoyed me, one of which being the fact that Company of Heroes isn't in the "simulation" genre on steam. It's not really a simulation, it's just inspired by World War 2.
The worst random things can happen to you in Company of Heroes, a random mortar lands on your sniper, killing him instantly. A grenade blows a hole in the ice underneath your German Tiger Tank (a
very expensive tank) and it sinks. In Starcraft everything is smooth and consistent allowing players to make calculated and precise plays.
You can also see Riot games patch their game League of Legends over the years to include less and less RNG, because people don't like it!
Competitive players don't like it!
I'll explain what I mean in this case. Years ago League of Legends had a stat known has dodge.
They tried to balance it, but in the end the only solution was to remove it entirely. Hey! It was a dumb stat anyway.
Critical hits are something else that is obviously reliant on RNG. While they didn't remove that stat they did make heavy changes to the way it works, making it so the player has guaranteed crits. If you have 10% chance to crit, you will crit 1 in 10 hits. No lucky 3 crits in a row!
No unlucky 1 crit in 30 hits!
Sounds amazing doesn't it?

But I don't think RNG in videogames is all bad. Usually this isn't my kind of thing, but personally I think casino games can be fun. My brother always tells me how fun the casino in real life is, but real life is overrated of course so let's talk about the videogames.
You make some decisions in most casino games - yes - but at the end of the day you're just rolling a die basically. Maybe you lose some, maybe you win some. Maybe you bust and your friend is sitting on a million
dollars! But there is a likeness to it, even though there is virtually zero skill. I think this is because these casino games don't operate under a false pretense. They don't pretend to be MLG material, 100% skills.
Company of Heroes tries to be an RTS, but it's RNG mechanics undermine the logical play style that an RTS needs to have.

RNG can lead to exciting, unexpected outcomes, but there are some places it just doesn't belong.