Vampirism should be treated more as a curse or a disease rather than an opportunity. Being a vampire is equal to gaining access to new skills and powers and the main character becomes stronger in certain types of situations, but you also have to deal with tons of restrictions and complications. The most drastic scenario is when you become a vampire "on hunger" (stage 4 of hunger - more on this topic below), because that's when encountered NPC's flee or attack the main character on sight and obviously this can pose a serious problem when it comes to completing quests. I strongly recommend that you familiarize yourself with every information provided in this section of the guide, so you'll know how to control your hunger when being a vampire and how to successfully get rid of vampirism.
Important! Main character can't become a vampire if he's already a werewolf. This is an excellent method to prevent yourself from getting this disease which forcers to take part in uncontrollable transformations. If you already are a werewolf and you want to try out playing as a vampire, then you must get rid of the lycanthropy curse. More on that can be found in the Lycanthropy section of this chapter.
How to become a vampire?
Vampirism can be caught the same way as most of the diseases do and this is by coming in contact with a certain type of an enemy. Obviously the only way to be turned is if you're infected by a person who is already a vampire and you should know that a large number of locations in the game's world are inhabited by them. Most of the vampires you meet will automatically be hostile towards you, however some of them will try to be friendly and try to mask their vampire nature (in this case you can provoke them to attack you). During your fights with the vampires you should notice that they like to attack you with a spell called Vampiric Drain (screen above). Using this spell grants a small chance of infecting the victim with vampirism and therefore making him a candidate to becoming a vampire (it doesn't happen right away).
You will know that you're on a right path to becoming a vampire when the game will inform you in the top left corner of the screen about catching a disease named Sanguinare Vampiris. The information on this disease will also appear in your active effects window (screen above), telling you about the curse and temporary health loss.
The game will now begin a very slow process of the main character transforming into a vampire. For the next three days you will be receiving informations at dusk and at twilight, telling you about a strange thirst and about weakness to sunlight. Aside from these messages you will also be witnessing image distortions (screen above).
Important! If you don't want to become a vampire, then you must act quickly! The main reason for that is because after the main character has become a vampire it will be much harder to get rid of the curse. There are two different ways of stopping the transformation process. The first method is to drink a potion which cures all diseases and the second method is to visit a shrine (doesn't matter which one) to receive a blessing (an easy way to find a shrine is to go to a temple located in Whiterun or Markarth).
After three days have passed you should receive an information about the vampire blood boiling in your veins and the transformation will be complete. You can perform an additional "confirmation" by noticing slightly different looks of the main character (screen above).
Main principals of being a vampire
Once the main character has finished transforming into a vampire he also becomes addicted to blood drained from the bodies of innocent civilians (screen above). The grand rule here is pretty simple - the more time has passed since the last "meal" the more hungry you are. This feature has its advantages and disadvantages. On the good side you can count on gaining access to new and/or more powerful vampire abilities. On the bad side you must deal with increasing problems of masking your true nature and also vampire's weaknesses become more annoying. The final fourth stage of vampire hunger is something you should avoid at all cost, because once you've advanced to it you won't be able to hide your vampire nature and you'll become an object of attacks performed by the people of Skyrim.
Drinking blood is a more complicated process than you might imagine, because you can't drink blood from a conscious person (in any way so attacking the civilians is also out of the question) or from a recently deceased person. The only way how this can be done is by interacting with a sleeping person, so being a vampire should be much easier for you if you're already a thief or assassin, because you'll have armors, perks and potions which improve your chances of staying undetected. It's fairly obvious that you should always start "the hunt" when it's nighttime, because that's when most NPC's go to bed.
If your vampire didn't advance to the last stage of hunger he'll have a much easier job, because he won't have to worry about his safety and he will be allowed to enter all areas normal people visit, including the bedrooms. Among good places where you can search for victims are barracks, castles, jarl's estates (Dragonsreach in Whiterun seems like a great choice) and other areas where anyone is allowed to enter. If on the other hand your vampire has reached the final four stage of hunger you'll have a more difficult job at finding potential targets, because you won't be allowed to enter the cities or other populated areas. In this case you'll have to be on a lookout for single huts located far away from the civilizations, as well as hunter campsites and khajiit caravans. You'll also need to rely on potions and spells (invisibility and silent movement) to stay hidden while trying to locate a person to feed on.
Each time you want to drink someone's blood you'll have to approach the sleeping person without waking them up, interact with them by pressing the E key and choose the left option from the actions list. It's extremely important that once the feeding starts it's not interrupted by anyone, so make sure to look around if no one is looking or heading your way. Drinking blood satisfies your hunger for some time and it also reverts you to the first stage of hunger. This means you won't have to worry about feeding for the next couple of days, but you should still make notes so that you don't wait too long and suddenly reach level four of hunger.
Vampire hunger stages
You start on this stage when you become a vampire for the first time and you also are reverted back to this stage each time you drank someone's blood (even if you were on stage 3 or stage 4 before that).
Changes made when stage 1 is active:
Receiving an active power called Vampire's Servant which allows to revive weak dead bodies for 60 seconds to fight alongside the main character.
Receiving an active power called Vampire's Sight which improves seeing things in the dark for 60 seconds.
Receiving an effect called Champion of the Night which increases the effectiveness of the spells from the illusion school of magic by 25%.
Receiving an effect called Nightstalker's Footsteps which reduces a chance of being detected while sneaking by 25%.
Receiving an effect called Immune to Disease which makes the main character 100% immune to all other diseases.
Receiving an effect called Resist Frost which increases the main character's resistance to frost damage by 25%.
Receiving an effect called Immune to Poison which makes the main character 100% immune to all types of poison.
Receiving an effect called Weakness to Fire which works like a disease, because it reduces the main character's resistance to fire damage by 25%.
Receiving an effect called Weakness to Sunlight which works like a disease and which is active only during a day. This effect (when active) reduces health, mana and stamina by 15 points and prevents them from being automatically regenerated over time.
Receiving a Destruction spell called Vampiric Drain which allows to absorb two points per second of the target's health.
Important - You can read more about the new powers and effects you've received by opening magic and active effects tabs.
You can "advance" to this stage if the main character didn't drink any new blood for some time. You'll be informed about it by an image distortion and a message saying that your vampire powers are getting stronger when you're hungry. This stage preserves all the powers and effects you've received on stage 1, however some of them are modified and new ones are added to the list. Here's a full list of changes:
Active power Vampire's Servant allows to revive dead bodies for 60 seconds to fight alongside the main character.
An effect called Resist Frost increases the main character's resistance to frost damage by 50%.
An effect called Weakness to Fire reduces the main character's resistance to fire damage by 50%.
An effect called Weakness to Sunlight reduces health, mana and stamina by 30 points during the day.
Receiving an active power called Vampire's Seduction which prevents people and creatures on level 10 or lower from escaping (it works for 30 seconds).
A spell called Vampiric Drain allows to absorb three points per second of the target's health.
You can "advance" to this stage if the main character still didn't drink any new blood and more time has passed. Just as before, you'll be informed about the transformation with an image distortion and a message saying that your vampire powers are getting stronger when you're hungry. This stage preserves all the powers and effects you've received on stage 1 and on stage 2, however some of them are modified. Here's a full list of changes:
Active power Vampire's Servant allows to revive powerful dead bodies for 60 seconds to fight alongside the main character.
An effect called Resist Frost increases the main character's resistance to frost damage by 75%.
An effect called Weakness to Fire reduces the main character's resistance to fire damage by 75%.
An effect called Weakness to Sunlight reduces health, mana and stamina by 45 points during the day.
A spell called Vampiric Drain allows to absorb four points per second of the target's health.
You can "advance" to this final stage if you've ignored all previous warnings and decided not to drink any blood for a very long time. Just as before, you'll be informed about the transformation with an image distortion and a message saying that your vampire powers are getting stronger when you're hungry. This stage preserves all the powers and effects you've received on stages 1-3, however some of them are modified and new ones are added to the list. Here's a full list of changes:
Active power Vampire's Servant allows to revive very powerful dead bodies for 60 seconds to fight alongside the main character.
An effect called Resist Frost increases the main character's resistance to frost damage by 100%.
An effect called Weakness to Fire reduces the main character's resistance to fire damage by 100%.
An effect called Weakness to Sunlight reduces health, mana and stamina by 60 points during the day.
Receiving an active power called Embrace of Shadows which once a day allows to improve the main character's sight and to become invisible for three minutes.
Hostile reactions towards the main character from all inhabitants of Skyrim.
A spell called Vampiric Drain allows to absorb five points per second of the target's health.
I strongly recommend that you prevent the main character from advancing to stage four of vampire hunger, because this can temporarily block the possibility of interacting with other people and completing most quests. Furthermore, it's very difficult to return from stage four to stage one, because you'll have to search for your victims outside of the big cities. The game tries to make it easier for you by giving you an active power which grants temporary invisibility, however if you aren't good at sneaking it won't do you any good.
Advantages and disadvantages of being a vampire
There aren't a lot of advantages of being a vampire and none of them is significant. Bonuses to sneaking may prove to be a nice addition to thieves and some of the spells may prove to be useful to mages, however you can obtain similar abilities and spells using other ways, usually much less complicated. The only unique advantage is a bonus to resistance to frost attacks and it may come in handy especially while fighting draugrs.
As for the disadvantages of being a vampire, there are A LOT of them and most of them are very important. The biggest disadvantage is that you can't control the curse the same way as werewolves can with lycanthropy. When you're a vampire you constantly have to monitor your hunger level to know on which stage you're currently on, because if you wait too long and advance to stage four it'll become very difficult for you to play the game normally (everyone becomes hostile towards the main character). Penalties to health, mana and stamina are also very annoying, because not only the bars are shorter, but they can't regenerate on their own if you're travelling during the day. This means you must travel mostly at night or have a lot of spells and potions in your inventory to manually replenish the bars and this of course complicates the game. The last important disadvantage is that vampires have reduced resistance to fire (even by 100% on stage four) and this is a serious problem, because a lot of enemies like to deal serious fire damage (including dragons).
To summarize, a chance to turn into a vampire should be treated more as a possibility, not necessity. You can decide to become a vampire, but you must pay attention to your hunger levels (make sure to save the game often). If you don't want any additional problems, then lycanthropy is something you should be more interested in.
Getting rid of the vampire curse
Important! Remember that you can stop the transformation from a human to a vampire thanks to cure disease potions and shrines found mostly in temples. The suggestions mentioned below are only to be used if the transformation has already been completed and the main character has become a "full" vampire.
In order to unlock the first method of getting rid of vampirism you must travel to one of the inns found in Skyrim and talk to the innkeeper. Ask the owner of the inn about the latest gossip and one of the information should be about a mage named Falion that lives in Morthal and studies the knowledge on vampires. The game should automatically unlock a side quest named Rising at Dawn and you must read its description to find out how to find Falion and how to get rid of the curse with his help (Falion will required a filled black gem).
The second method of getting rid of the curse is to fulfill all the requirements needed to become a werewolf. This means you'll have to join a group of warriors called the Companions and they occupy a Jorrvaskr sanctuary in Whiterun. Start doing quests for the Companions and you'll have a chance to turn into a werewolf for the first time while completing Silver Hand quest (screen above). This is when the vampire curse will be lifted. Make sure to read the chapter about the Companion quests and the section about lycanthropy for more details.
Important! Even if you get rid of vampirism (or stop the transformation) you can still become a vampire again if you catch the disease later in the game. The only exception is if you've decided to turn into a werewolf, because people affected by lycanthropy are immune to all diseases, including vampirism.