Skyrim is, as you may be aware, a pretty massive game. Without even accounting for the cartoonishly-high number of mods out there, the fifth Elder Scrolls game is basically endless. So, naturally, with that much space to toy around with, Bethesda left a bunch of weird little details hidden throughout - and a lot of non-hidden stuff that you just never noticed because the game is so stupidly big that lots of people who plunked over 100 hours in never even finished the main storyline.
Fire magic is pretty useful for lighting oil slicks strategically spilled in bandit hideouts (they should really be better about cleaning those up) and generally burning the shit out of anyone who gets in your way, but it can also do basically meaningless stuff that's nonetheless hugely entertaining. Example: you can use fire magic to boil water.
Yep, just go up to shallow waterways (like in Whiterun), blast some fire out of your hands, and watch the steam and bubbles come up. Nice attention to detail, Bethesda!
Not enough though, which is why I installed 90 mods that let me light butterflies on fire.
Thought you had faced down every Dragon Priest, Legendary Dragon, and Named Monster that this slice of Tamriel has to offer? Guess what - probably not.
Well, honestly, you probably DIDN'T think you had, because you're aware of just how massive Skyrim is. So it should come as no surprise that there are (at least) 3 hidden bosses strewn about Skyrim - although you'll need the DLC to face them all. If you only have the vanilla Skyrim experience, then you can at least take on one of these bad boys.
The first requires you to head down to everyone's favorite surreal Dwemer ruin, Blackreach. There's an enormous orb towards the center of the underground cave that's pretty hard to miss - just stare into it, give it the ol' Unrelenting Force shout, and BOOM! Now you're fighting an underground dragon known as Vulthuryol. It's not a particularly difficult dragon, but it's at least tough to find. Plus, there's a nearby giant, which (assuming you didn't already kill it) pretty much guarantees a dragon/giant battle.
The second one requires the Dragonborn DLC, which you should probably have anyways because it LETS YOU RIDE A DRAGON (fair warning: riding a dragon is way less cool than you'd think). But if you do have it, you'll get to fight a boss that's a throwback to the good ol' days of Morrowmind (well, Morrowind's Bloodmoon expansion): the ghost of the Frost Giant king Karstaag. To summon him, you must retrieve his skull from the Glacial Cave, placed on the throne at Castle Karstaag Ruins, and you'll get to fight his spectral form.
It's a tough fight, but the reward is pretty neat - you will gain the ability to summon the ghost of Karstaag, but only THREE times ever, and only when outdoors.
And the third secret boss is The Reaper, only available in the Dawnguard DLC. First, you need to head to the Soul Cairn, and from there head in to the Reaper's Lair - place three Reaper Gem Fragments on the altar, and get ready to fight THE GRIM REAPER.
Sure, the Thieves' Guild is something of a mess in Skyrim (at least, compared to the glory days of Oblivion) - they're reduced to living in the sewer like some friggin' Ninja Turtles, there are traitors running amok, and YOU - a completely new member who spends a lot of his or her time yelling at dragons - are pretty much their only hope in the world. But - they're still the Thieves' Guild, and have a bit more going on than you might notice. For instance, check out pretty much any building in Skyrim, and you'll see that the Thieves' Guild have left their mark there.
Yes, ANY building.
Well, okay, not ANY building, but definitely a whole bunch. The markings are called Shadowmarks, and basically work similar to the way Hobo Code markings would work. And in case you're not familiar with the Hobo Code (either due to not being a hobo in the 1930s, or not seeing that one episode of Mad Men), here's basically how it works: there are a bunch of symbols that members of the Thieves' Guild can leave on a building to communicate things about the building or its owner to other members, but would be indecipherable to anyone else. There are symbols that indicate the owners are members of the Guild, or enemies to the Guild, or that the store has already been plundered and there's nothing valuable inside, or a bunch of other things.
Whiterun and Riften (no surprise there) have the most Shadowmarks, but there are a number of them strewn about the rest of Snowy Dragon Land USA.
As is common with caves in Skyrim, the cave at White River Watch is teeming with bandits - but there's one bandit who's not much of a threat: Ulfr the Blind. His non-threatening nature should be pretttttttttty obvious (hint: he is NOT the fantasy version of Matt Murdock). But what's really great about Ulfr is that - despite being blind - he's something of a bookworm. And what makes that EVEN better is that THIS is Ulfr's book:
Most games wouldn't allow you to basically become an Indiana Jones villain, but Skyrim isn't most games - there are certain enemies you can kill by sneaking up behind them and RIPPING THE HEART OUT OF THEIR CHESTS. Sorry, Forsworn Briarhearts, but you got a rough deal in life.
The Forsworn are scattered about the Reach - hyper-aggressive tribal types who like to hang around hagravens. And most have a Briarheart as their leader, with the unfortunate weakness of being a semi-undead being whose normal heart has been replaced by a Briarheart. And if your Sneak skill is high enough, you can pickpocket their Briarheart right out of their chest, instantly killing them in a badass-yet-horrifying way.
Here's a weird thing - first off, there are mammoths who AREN'T tended to by giants. Second, you can distinguish the two by the tusks.
Regular mammoths have tusks that look like this:
...whereas owned mammoths have tusks with these markings on them:
So, now you know how to tell mammoths apart! Also, another way of telling if a mammoth is owned by a giant or not is whether there is a giant blasting you into the stratosphere at this exact moment.
Did you just kill a dragon and aren't sure where its skeletal remains are? The visual hint of "the enormous dragon skeleton that I just sucked a soul out of" not enough? Well, worry no more, because dragon remains actually show up on your map!
Get a map marker out to REALLY rub it in that you slaughtered a dragon by yelling at it.
While the residents of Skyrim look like mere ants in the eyes of Alduin, there are a bunch of ACTUAL ants you never saw (unless you installed the Turn Dragons Into Ants mod). Crawling on certain tree stumps, logs, and patches of land throughout 8-Voices Viking Country are lines of ants, crawling around and trying to build up their ant farms and not get involved with any of this dragon/civil war silliness.
If you walked up the steps to High Hrothgar, congratulations! You did it the way the game intended, instead of the other 90% of us who got to the base of the mountain in the wrong spot, and figured "yeah, this won't be too tough to climb up by hopping and sprinting repeatedly."
And if you walked up the steps as intended, you probably noticed the etched tablets along the way - but one thing a lot of people probably wouldn't be aware of (at least I wasn't) is that if you activate all 10, you'll receive a temporary perk known as "Voice of the Sky," which will stop any animal from attacking you or your followers for 24 hours. Not 24 in-game hours either, but IRL actual hours (unless YOU attack an animal first, in which case you're fair game to bears again).
Credit goes to HystericMarine for finding this - the perfect encapsulation of HOW detailed Skyrim is as a whole.
Once you prove to the Jarl of Whiterun that dragons have returned to Skyrim, he orders his housecarl Irileth to dispatch some guards to Riverwood...
...if you follow Irileth as she leaves Dragonsreach, she doesn't just disappear or teleport to another room, but walks down the steps and across Whiterun...
...to arrive at a meeting with one of the guards, telling him that he'll need to gather a few other guards and head for Riverwood.
They converse about how many guards Whiterun can afford to send, what the realities would be of a few guards against a dragon, and the importance of protecting Riverwood from whatever may attack it.
The guard is met by two others, and they leave the town....
...but instead of teleporting to Riverwood, you can follow them all, in real time, as they make the trek (although one may run while the rest stroll calmly). Eventually, all three will arrive in Riverwood...
...and continue treating you the same way they always have.