Phlebotomy kit

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Name	phlebotomy kit
Appearance	phlebotomy kit
Base price	500 zm
Weight	25
Material	leather
Monster use	Will not be used by monsters.

A phlebotomy kit is a type of tool that appears in dNetHack, notdNetHack and notnotdNetHack. It is a medium-sized chargeable tool that has a base material of leather.

Generation

Undead Hunters start each game with an uncursed and uncharged phlebotomy kit.

Phlebotomy kits make up ¹⁄₂₀₀ (0.5%) of all tools that are randomly generated on the ground, in shops and as death drops. Randomly-created phlebotomy kits are uncursed and generate with up to 5 charges.

Altars that are aligned to defilement (not counting altars in the Undead Hunter quest or any high altars) will have a phlebotomy kit generated on their square.

Treesingers are capable of making copies of phlebotomy kits if the hero shows them one—phlebotomy kits made this way will be made of cloth and will always be uncharged.

Description

A hero applying a charged phlebotomy kit will prompt the player to perform a blood draw, using up a charge to create a potion of their blood that will be the same beatitude as the kit. The potion will be diluted if the character is hungry and undiluted otherwise. This process reduces the hero's current HP by ¹⁄₂ of their maximum HP, and the hero will be unable to draw their own blood if this damage would leave them with less than 1 hit-point. Drawing their own blood has the following effects:

• Abuses constitution
• May increase their blood impurity with a ¹⁄_{blood impurity} chance (first time is guaranteed).
• Will have their nutrition lowered by ²⁄₅ of the nutrition value for the monster representing that hero's starting race, or half as much if the potion created is diluted.
• Drains ³⁄₁₀×(cXP - pXP) of experience, where cXP is the amount of experience required for the hero's current level, and pXP is the amount required for the previous level. This may drain a level if this would put them below their current level's XP threshold. Refer to this table for a level-by-level breakdown for XP loss.
• Wielded or offhanded shanta-pata will become bloodied for 10 (more) turns.

Transfusing blood

If the hero is carrying a phlebotomy kit, applying a non-cursed potion of blood from a monster that shares the same racial monster attribute flag as the hero will perform a blood transfusion, which can raise the hero's blood impurity as above, and consumes the potion for varying effects based on whether the hero is a vampire and the potion's beatitude. Currently, obtaining the blood clone reanimation upgrade will block a hero from performing transfusions, but not from drawing blood. Regardless of race or beatitude, transfusing blood will also always grant any effects as would have occurred by quaffing the blood directly: e.g. cockatrice blood will cause instant stoning, and floating eye blood will convey telepathy.

Vampires

• If the hero is a vampire performing a transfusion with the vampire blood (normally unacquirable outside of phlebotomy kits themselves), they will exercise constitution and be healed for an amount of HP equal to (4 * Maxhp) + 910, even if cursed blood was used—they additionally gain 120 nutrition for cursed blood and 80 otherwise. The nutrition gain is halved if diluted blood was used.
• If blood of another race was used, they will heal for 2d8 HP and gain the same amount of nutrition as if they had quaffed the blood directly: this will be ³⁄₁₀ of the nutrition granted by eating the corpse if the potion used was cursed, and ²⁄₅ of the nutrition value otherwise. The nutrition gain is halved if diluted blood was used.

Non-vampires

• If the hero performs a transfusion with non-cursed blood of the same race, they will exercise constitution, heal an amount of HP equal to (4 * Maxhp) + 910 (or approximately ⁴⁄₁₀maxhp + 1), gain 100 nutrition (or 50 if the blood is diluted), and will also cure illness if the blood was from a blessed potion.
  • If cursed blood is used, they will suffer a heart attack and take lethal damage equal to ¹⁄₃ of their maximum HP and gain no nutrition.
  • If blood of another race is used, they will develop a non-vomitable illness (signaled by the usual message for contracting illness) and gain no nutrition.

Once completed, transfusions will attempt to add a charge to the first phlebotomy kit found in inventory based on alphabetical sorting from a–z, and then A–Z. If the chosen kit already has 15 charges, the charge is instead lost. As with drawing blood, using a phlebotomy kit to perform a transfusion while wielding a shanta-pata (or its twingun shanta form) in either hand or else having the weapon in their alternate weapon slot, will bloody the weapon for 10 (more) turns.

Blood transfusions do not count as cannibalism, unlike quaffing blood, but can still cause choking from over-nutrition, and also cannot increase maximum hit points. A monster of the same race as the hero will always have compatible blood regardless of any other racial traits they may have, e.g. an orcish hero can infuse themselves with blood from orcs of the ages of stars, who are both orcish and elven.

Research

A hero of any role with a phlebotomy kit in their open inventory can proceed down the defilement research path if they have an active defilement glyph implanted (a minimum of 27 insight is required for the thought to become active): applying a phlebotomy kit after having performed sufficient defilement research will display the option to "exsanguinate yourself" (corresponding to the preservation research path). A hero who started the game as a vampire will also see the option to "distill your blood" (corresponding to the vampire defilement research path). Preservation research has 6 upgrades, while vampire defilement has 7, and both paths are linear—progression in either path counts towards making a "great breakthrough" and meeting the conditions for a full-scoring ascension, which requires a minimum of 6 upgrades total from either or both of the research paths. While characters of other roles may still perform undead hunter research, they cannot ascend under an undead hunter ascension.

Selecting either option will advance the hero in their research and grant an appropriate upgrade, while also reducing their current and peak intelligence and wisdom scores by 1 (which is normal for abuse of attributes in dNetHack compared to other variants). Every third upgrade taken on the research path will also permanently reduce the maximum intelligence and wisdom possible for that character (e.g. from a worn helm of brilliance) by 1; this also stacks with reductions from parasitology research. A hypothetical hero that completes both defilement research paths will thus have their intelligence and wisdom maximums reduced by 4, producing a cap of 21 for each compared to the normal 25.

Strategy

Undead Hunters will want to reserve their starting blood potions for use with their starting phlebotomy kits for emergency healing, since they cannot pray, and since and most of them will not be able to procure a more reliable healing source until the mid-game. Early on, drawing blood always carries some risk unless performed in a safe environment such as Sokoban where no monsters can generate, and drawing more than one potion at a time will leave the hero with only a sliver of their health, or even just one hit-point, likely resulting in sudden death. An Undead Hunter can use the kit to keep their experience level low for purposes such as protection rackets, though this means temporarily foregoing the intrinsic speed that they normally gain at XL 7.

Undead Hunter heroes that have not found a tinning kit and corpses of their own race to produce blood with will want to consider starting to draw potions of their blood (and preferably baging them for safekeeping) for long-term use in emergencies around XL 8, replenishing XP when it would put them below their current threshold. A hero is making use of phlebotomy kits is not guaranteed to have any means of replenishing potions lost to hazards such as fire damage or cold damage, and sources of charging and additional phlebotomy kits may be quite sparse throughout the early dungeon. Among the more reliable options, a hardware store or lighting store shopkeeper (e.g. in Minetown or Gatetown) may offer charging among their services, and Undead Hunters will find additional phlebotomy kits accompanying any altars to defilement they encounter in the dungeon.

Non-undead hunters who come across a phlebotomy kit may wish to use it as a means of emergency healing as well, but are dependent on either random generation providing them one or polypiling for it otherwise. In most cases, their high hp cost makes them more trouble than they're worth when compared to other sources of healing. Since no more than 2 potions of blood can be pulled out of a phlebotomy kit at a time without external healing, they also do not make for a particularly good source of potions of blood. They will be of most use to characters whose hp total far exceeds the 400 hit-points provided by potions of full healing and also have access to tinning and corpses of their own race.

The phlebotomy kit's greatest strength in the early game also proves its greatest handicap at higher levels: as the hero progresses and gains further experience levels, the experience drain becomes much more costly, and the hero may be able to surpass the healing properties of transfusions with alchemy to make potions of extra healing and potions of full healing. In regard to handling matters of intelligence and wisdom loss, binding the spirit Huginn and Munnin will set the hero's intelligence and wisdom to 25 for the duration of the binding.

Origin

Phlebotomy is the process of making a puncture in a vein, usually in the arm or hand, with a delivery tube (or cannula) for the purpose of drawing blood. The procedure itself is known as a "venipuncture", which is also used for intravenous therapy—therapeutic phlebotomy is carried out in the treatment of some blood disorders. A person who performs a phlebotomy is called a phlebotomist, although most doctors, nurses, and other technicians can also carry out a phlebotomy. The phlebotomy kit of dNetHack is partly based on the large leather medical bags employed by Victorian-era general physicians making house calls, as well as doctors using the bag as a travel apothecary or medicine chest—the kit also evidently contains the tools required to draw and handle blood for various purposes, such as intravenous injections and bloodletting (and apparently instructions on operation, since it is not at all restricted by the hero's role).

The item is also based on the 2015 action role-playing game Bloodborne, where players create a protagonist known as a Hunter (the basis for the Undead Hunter of dNetHack) and try to find the source of a blood-borne plague which transforms the residents of the decrepit Gothic and Victorian-era inspired Yharnam into horrific beasts. These Hunters carry blood vials in their packs that they can use as a source of healing: the blood vial is a mysterious form of serum that is administered by the Healing Church and used in blood ministrations such as the one the player character undergoes in the game's opening cut-scene.

The blood vials of Bloodborne are visibly inspired by early real-world attempts at blood transfusion, as well as bloodletting and other pre-germ theory medicinal practices. The first successful human-to-human blood transfusion was performed by James Blundell in 1818, though it would not see widespread adoption in medical practice until the first World War: early transfusions carried a high mortality rate due to lacking an understanding of blood types (established by Karl Landsteiner in 1901) and the necessary sterilization of equipment, as incompatible blood causes the recipient's immune system to reject the donated blood and results in clotting within the circulatory system; this in turn can lead to several symptoms such as chills, chest pain and nausea, and if left untreated can lead to illnesses such as anemia, acute kidney failure or entering complete shock, eventually cascading into multiple organ failure and death.

The risks of early blood transfusion are reflected in the effects that occur when a non-vampire hero in dNetHack and its derivatives uses a phlebotomy kit to transfuse blood that is cursed or belongs to an "unrelated" monster. Conversely, vampires are unaffected due to being unholy creatures that require blood in order to survive (hence cursed blood being more effective), and they are also traditionally portrayed as capable of consuming any type of blood that is not intrinsically dangerous to them.

Messages

Draw your own blood?

You applied a phlebotomy kit and are prompted if you want to use it.

You feel invigorated.

You successfully performed a transfusion with blood from a monster of your race.

Your heart stops! When it finally beats again, it is weak and thready.

You suffered a heart attack from transfusing cursed blood.

You drain some blood from your body.

You obtained a preservation upgrade using the phlebotomy kit.

You're too injured!

You attempted to draw blood while below ¹⁄₂ of your maximum HP.