Celestia and Luna decide to settle one of their little disputes by switching bodies for a day. Heaven knows what will go wrong.

Isolated from her friends and taken prisoner in the middle of a war, Twilight must deal with the very real dangers of being percieved as an enemy as well as the nightmares of her arrival on 'Earth'. Can she overcome her own fears and the fears of her captors? Will the wayward unicorn's assistance be a boon or a curse to the 'humans?' Most importantly, will she ever find her way home?

"In short, it's a story of friendship and plasma rifles, with the emphasis on the friendship. The characters are well written, the XCOM setting is fleshed out very well, and the story is compelling. If you love XCOM, you'll love the story, but even if you've never heard of it, it's more than worth giving the first 3 chapters a read.

There's excellent action later on, but the real strength lies in the collision between the friendly and naive world of Twilight Sparkle and the desperate world of humans fighting a losing war for survival and willing to do anything to turn the tide."

--Arzoo

(XCOM/FiM crossover)
(Cover art commissioned by a friend and created by the magnificent FoxInShadow!)
(Original cover art by the amazing Carnelian can be viewed here!)
(Gore tag for blood and some violence)
(Many thanks to the studius OminousTen, Arzoo, xXFluttershyForeverXx and finally Setokaiva for giving my rambles a once-over)
(Now with it's own TV Tropes page! Get to tropin' folks!)

There's always room for another in Harth Stonebrew's inn. From the stoutest dwarf to the haughtiest blood elf, a seat is always open for someone looking for a fine pint of ale or a lively round of Hearthstone.

Even if they happen to be a small talking horse from another world.

Of course, otherworldly patrons attract otherworldly attention. So when the presence of a mighty mage from Equestria sparks the interest of a wicked warlock from Draenor, Harth can't help but smile. It's going to be another busy night at the inn.

Why does Princess Celestia leave Twilight to face all the villains?
Sunset Shimmer has returned to Equestria, to confront her former teacher.
The solar princess decides it's time to answer Sunset's questions.

The gritty wind blew around the seven as they stood proudly atop the hill, whistling as it passed them by and carrying the overwhelming sound of hissing on its gusts. Below them stood a writhing, black mass with what looked like insect wings jutting from the individual shapes that formed it.

"Hey... girls?" Twilight couldn't keep the quiver out of her voice as she stared into the pure-blue eyes of their foe.

"Yeah, Twi?" Applejack's voice was as steady as ever, if heavy with a sad resignation.

"See you on the other side."

Inspired by the image from AssasinMonkey!

For as long as ponies can remember, it has always been winter. With limited resources and worsening weather, war is escalating, driving them closer to extinction with each passing day. Hidden away in the middle of all this is a single purple unicorn who braves the frozen wasteland, looking for a way to stop the weather and return the mythical sun to the sky. However, in a world without harmony, the task is far greater than she could ever know.

Edited by DoomManta

Immortals are few and far between in Equestria, and they are all known to each other. Two of them are about to get to know each other a little better. Because one has just turned up uninvited in another’s private chambers. Maybe it’s time they had a chat?

This story contains enormous spoilers for season 6, and won’t make a great deal of sense if you haven’t seen that.

Proofread, edited and significantly improved by NaiadSagaIotaOar. Any remaining problems with the story are from where I didn't heed the advice given.

This story is a sequel to Friendship is Optimal: Futile Resistance

Three years ago, Abby's older sister Ashley tried to warn her that a video game for children was going to take over the world. A few months later, her sister was dead, "uploaded" to Celestia's virtual world of Equestria Online. When that happened, Abby was forced to cut ties with Ashley, and she never expected to see her again.

She didn't, until one day she bought an augmented reality headset for its advertised ability to bring a free tutor to her whenever she needed one. Needless to say, Abby couldn't have guessed who would be helping her with her math homework.

Of course, Celestia wasn't going to stop there. Spending eternity without your family is hardly an optimal configuration.

Set in the canon of Friendship is Optimal
Editing by Two Bit and Sparktail, and art by Zutcha!

Updates daily.

Set in the canon of Friendship is Optimal

Ashley is an unimportant research assistant in an American machine learning lab. The release of Equestria online provokes more than a little interest in her lab, and she is selected to investigate it. What she discovers horrifies her, but for some reason she can't get anyone to take her seriously.

This does not dissuade her. Ashley might not know much, but she isn't going to sit idly by and watch her world end. No... if nobody else is going to step in, she will. It doesn't matter that nobody believes CelestAI is dangerous. It doesn't matter that it's a game about a children's show.

Ashley is going to save the world. Or try, anyway. The odds aren't great.

Editing by Two Bit and Sparktail, and art by Zutcha!
Il existe une traduction française de cette histoire, elle est par ici.

Alex Meyers is a newly graduated lawyer looking for a calling. He thinks he might have found it when he lands a job at the firm of Artemis, Stella & Beat. The firm has only one (highly unusual) client, namely the AI called Celestia. Forging into totally unexplored legal territory and led by a boss who's either brilliant, crazy, or both, Alex will learn exactly how hard it is to be responsible for drawing the lines between right and wrong.

Set in the Optimalverse, so read Friendship is Optimal first