Magic in this era.
Its been a good 500 years since the events leading up to Twilight’s ascension to princess-hood and the spliting of Equestria into the Astral Principality, the Lunar Republic and the Solar Empire. Everything changes in 500 years of time. Ideas, Technology, Art, and Perceptions. And heading these changes is Derpy institute, shinning jewel of Twilight’s land.
Derpy and Time Turner were well known for their research into unconventional magics and steam engine based technology. Three years after the split, Derpy discovered the magic of earth ponies, Wordsmithing.
Normally, such latent magics wouldn’t have an effect on day to day life on a normal pony. For example, majority of bards, singers, fiction and non fiction writers, trades ponies, diplomats, and farmers are earth ponies. The reason being the latent magic of Wordsmithing or using words to unconsciously work the world around them.
But like unicorns and pegasi, magic levels and talents vary from pony to pony, and some earth ponies are stronger than others. One prime example would be Pinkie Pie. Her magic went beyond being able to skillfully string words together or shouting hard enough to warp the magical and thus physical fabric of the world. She was gifted with the ability to either cause the world fabric to warp around her or predict the future through her pinkie sense, enforce certain actions on other ponies through the magical contract of a pinkie promise, enchant, organize, and harmonize a city no larger than Canterlot for either a party or a song, create improbably things simply because she believed they could work and finally perform and perceive physical law breaking activities on a normal basis such as the mythical fourth wall and breaking said object.
While no pony has been able to fully document the mechanics of earth pony magics, autopsies have revealed that earth ponies have two carbuncles unlike ever other pony. One is located in the brain and acts as a storage center for every word this pony has spoken, reavealing the truth behind there amazing memory and skill at either always telling the truth or lying so well it is impossible to catch them. The second is located in the heart and acts as a focus point for there natural magics to gather and be released.
After that it is like unicorn magics in a pony needs only focus on what they want and release for the job to be done, but seeing as earth pony magics are centered in the heart, this process is often done hundreds of times a day without any conscious thought.
The magic schools that teach Wordsmithing often start young and spend a minimum of 5 years teaching them how to first sense and control this magic and then teaching them how to control it. Spells are not written down but rather made up on the spot as needed.
One final note, The Lunar Knights are the only military force to employ an entire platoon of Wordsmiths.