This is the first official add-on for Skyrim called «Dawnguard».
It tells the story of a vampire lord by the name of Harkonnen. All he wants - is to end the war and win over the fact that he hates the most - the sun;
There is a choice of one of the two sides of the intensifying conflict: vampires or vampire hunters, known as the Guardians of dawn. Depending on the choice of the parties, content (content that adds to the game addon) will vary considerably;

Some quests storyline takes place in one of the planes of Oblivion - Cairn Shower;
In the tavern Riften "exuberant jar" bosmerka Galatians can help you to change facial features in just Septims 1000, but it will not allow you to change the race or sex of the character. Note that it will help you only if you are not a vampire;
Lovers to build new branches skills for their characters also have something to rejoice: two new talent tree - vampirism (Form vampire lord) and lycanthropy;
You will be able to turn into a vampire lord, if you side with Harkonnen. But even if you go along the path of vampire hunters, you can still become a vampire lord. This will add a look of your character a lot of new features. Optionally, you can always revert back to human form;

In Wrath, new dragon shouts. One of them is called the gap of the soul. This will help draw out the soul cry from the defeated enemy and use it as an ally;
Also in Dawnstar, Windhelm and Solitude now are ferries that can carry you and your fellow travelers between the two cities for 50 Septims and to the pier icy waters (Castle Volkihar) 500 Septims;
Now you can fight on horseback. Can be used as a one-handed weapon and a crossbow or bow, but no staff and no spells.
There was a weapon of the dragon bones.
There are new kinds of finishing moves.