today i finished a quest in skyrim that could be considered epic. the aetherium forge quest line. it was long: find 5 locations, clean out 4 dungeons, fetch 4 items. it was hard: 4 dungeons, 3 boss battles, one super boss battle. and it was sort of grand scale: unique bosses, lots of high level drauger (my character is about 45th level), and a unique magic item at the end.

nice to have things included a good backstory, extensive dialog with voice over, and some settings on a grand scale (such as the forge) - IE impressive looking locations. the director john ford, famous for epic westerns used monument valley for many of his films. and cecil b demille, famous for his epic films, often used extremely large and lavish sets with hundreds or thousands of extras.

the main quest line in skyrim could also be considered epic. its long, hard, and rather grand scale, what with elder scrolls, travelling to soverngard, and stopping alduin from destroying the world, and all that jazz.

Thats an interesting approach to take TES into account. I have played Skyrim (and propably the other TES's) for over 160 hours each. The backstory of Skyrim in my thought was a bit oldscool. There was a tyrant, people get rid of it, it returned and made evil things again, people go and fight for him (where I also anticipated with both sides the North and the others). Sure it was big scaled, long and partialy boring to travel from one location to the other but this wouldnt make it epic automaticaly. It is more the kind of a main quest to be big scaled and long (remembering the deadra fight in Oblivion before the big boss crushed the capital city) but does this imply that all main quests are epic?

The aetherium forge was a very interesting quest I have done with pleasure in Skyrim too but here it wasnt the loot or boss fights or even the location (yeah the 400ds dwemer ruins -.-) but the colaborating character Katria and her back story that made this quest interesting and the finaly loot something unique (for me). I feeled sad as she was gone because I liked her from the wide mass of characters most in Skyrim additionaly to the Vampire DLC NPC.

The world of TES lives from such quests and unique characters with individual story but what bout other games (maybe from Bethesda)? Fallout 4 has had some interesting quests and a more or less unique main story but the most epic moment here was getting into the Institute and the quest of buildg that mashine to do so or conquer the castle. Anything else seemed very similar and repetitive. So not epic to me.

What about something like Doom 3, does such games cant have epic parts at some point (even without "quests")?

What is an epic ?

Originally epic was a genre or style of poetry.

Unlike let's say love poems, or religious hymns, it was the kind of versed text that told the story of one or more legendary characters.

Here is one thing to think about: Instead of trying to find the meaning behind abstract words like 'big' or 'long', try to answer yourself the question:

"Is what is happening in the quest worthy to become a legend ?" Like, if the events taking place in the quest were actually happening in a world, would

they be considered important enough from the people of the world to memorize them and write stories about them ?

If the answer is 'yes' you are in the right track.

Now, most epic stories tend to focus on the struggle of one or more characters to achieve something.

The Iliad focuses on Achilles's struggle to overcome his rage. The Oddessey on Oddesseus's struggle to return home.

Star Wars episodes 4,5,6 on Luke's struggle to put an end to the dictatorship of Palpatine.

Yet if the characters just achieved their goals in 1 page / scene, these wouldn't be much of epics, would they ?

As they say "It's the journey that matters, not the destination".

So an epic usually tells the story of some character(s) to achieve something, but until this is achieved, a number of

things happen, often with consequences affecting others, not necessarily the protagonists.

The Iliad spends a whole paragraph telling the background of a character the moment he appears, who dies in the end

of the very same paragraph:

That's just an example of how an important feature is to show how others, non protagonists are affected.

It's an interesting question and not an easy one to answer it seems. Personally I think that "epicness" is more a matter of style than it is a matter of content.

You could tell an epic quest about looking for a lost cat or going to the next village to buy potatoes. It's certainly something that has been done before in the realm of comic/parodic fantasy. The content of your epic quest is only important regarding the rest of your IP : it has to be coherent with the world you crafted, the rules of this world and the expectations that it sets for the player. An epic quest about potatoes can work in a satirical game, but it can't in a more serious game.

There are a lot of answers here that detail the common expectations people have for epic content in traditional/serious games, so I won't add to it. Mostly it's about "grand scale", "high stakes" and "uniqueness".

Instead I will focus on what makes a quest epic in terms of style :

Anticipation : epic quests need a build up, they often don't start as epic quests but become epic quests. How many great epic stories start small, with an orphan on a farm ? The feeling of epicness is not really about things being big, it's about things being bigger : bigger than the character, bigger than what they originally seemed to be. Mystery is a great way to do that, as you uncover the mystery the true goal/scope of the quest appears.

Milestones : if you don't know the end goal of your quest from the start, you need secondary goals, milestones, to create a drive for the player. Even if you do know the end goal from the start, milestones are a great way to make your quest feel bigger than it really is. Epic quests are adventures, not a single task but rather a succession of tasks accomplished in the pursuit of a greater goal. They don't need to be long, but it's certainly hard to cram both a build up and multiple steps into a short quest.

Overwhelming : epic quests are overwhelming for the character (and therefor the player), at least in the beginning. When the player finally realizes the full scope of the quest, he needs to be overwhelmed by it. The quest is epic because it's so much bigger than him and there is no apparent way to complete it (at first) and yet the player will eventually complete it. It's the feeling of overcoming what seemed to be impossible that separates epic quests from standard quests.

Conflict/Struggle : you can't make an epic quest without difficulties for the player to overcome. Whether it's the endgoal in itself or obstacles along the way or both doesn't really matter, you just need it. It doesn't mean that epic quests must be difficult, it means that they must appear difficult. If your character is an all powerful all knowing wizard, it's gonna be very hard to send him on an epic quest because there aren't really any difficulties (only one would be himself) you can put in his way so the quest ends up feeling more like a chore than an epic journey.

Consequences : epic quests have clear and meaningful consequences for both success and failure. It's not enough that you have this epic journey for your player to engage in, there needs to be a good reason to motivate him to undertake that journey. Whether it's very personal, like revenge, or more global, like saving the world (that your character is a part of and/or cares about), is unimportant. What is important is that the player is aware of the consequences of failing the quest and that he cares about it. Epic quests are not things you do on the side, they require full commitment, they must feel important to the player even if they are not.

Dressing : in the end, making an epic quest is not really about the content of the quest but rather how you present it. You can make almost any quest feel epic if you emphasize the struggle, the consequences and the journey itself. The journey towards the goal is more important than the goal of the quest or the possible rewards for completing that goal. That is why epic quests are the stuff of legend, because the story itself is worth telling and not just the end game.