Blood Moon



A Blood Moon is a random event that takes place at night, from 7:30PM to 4:30AM, affecting only the surface layer. A Blood Moon can also be initiated when the player uses a Bloody Tear. It causes several hazards for its duration: Enemy spawns increase, even near the player's Home and NPCs (where enemies do not normally spawn), Zombies become able to open Doors, and Bunnies, Penguins, and Goldfish transform into dangerous enemies, along with other effects (see below). Blood Moons are signaled by the message "The Blood Moon is rising..." in the lower left corner of the screen (or the top middle of the screen on ). The moon, sky, water, and rain will appear red for the duration of the event. A reddish-pink filter will also be present in all above-ground areas. Blood Moons disable the ability to speed up time whilst sleeping in a bed.

Criteria
In order for a Blood Moon to naturally occur, the following criteria must be met:
 * It will only occur if at least one player in the world has more than 120 health.
 * It can only occur on nights when the moon phase is not new moon.
 * It will not occur if the Eye of Cthulhu will spawn on that night.
 * Given the above criteria, a Blood Moon has a chance of occurring, determined at  each night.

A Blood Moon can be initiated manually at nighttime by using a Bloody Tear and does not require said criteria to be met.

Enemies

 * The spawn rate of enemies on the surface increases., , The Groom, , and the Clown (if in Hardmode) have a chance to spawn. Enemies not only spawn faster, but more are spawned than can normally exist on-screen at once. This works no matter the environment, so Corruption and Crimson enemies can also swarm even more than they normally would, for example.
 * Enemies can even spawn near NPCs and their houses, whereas those usually suppress enemy spawns. Player-placed walls are not necessarily safe during this event.
 * Zombies and their counterparts can open Doors.
 * Goldfish become Corrupt Goldfish/, Bunnies become Corrupt Bunnies/, and Penguins become Corrupt Penguins/. Those spawned from Statues are Corrupt or Vicious, and they do not revert to regular Goldfish or Bunnies after the Blood Moon is over. If it is raining during the event, transformed Goldfish will flop around on the ground, rather than walk.

Sold items

 * The Merchant sells Throwing Knives.
 * The Arms Dealer sells Silver Bullets (in, only if silver is present in the world), and if tungsten is present (Pre-Hardmode. In Hardmode, the Arms Dealer will always sell Silver or Tungsten Bullets ).
 * The Clothier sells the Mime Mask, and.
 * On the, he will also sell George's set for male players, and the Fabulous set for female players.
 * The Dryad stops selling Purification Powder, Sunflowers, and Grass Seeds.
 * If the world was created with the Corruption (or she is in a Graveyard in Hardmode), she will sell Vile Powder and Corrupt Seeds.
 * If the world was created with the Crimson (or she is in a Graveyard in Hardmode), she will sell and Crimson Seeds.
 * On the, she will also sell Sparkly Wings during Hardmode.
 * The Painter sells the Evil Presence painting.
 * The Dye Trader sells Bloodbath Dye.
 * The Steampunker sells Purple Solution if the Corruption is present, or Red Solution if the Crimson is present instead of Green Solution.
 * The Cyborg sells Rocket II ammunition.
 * The Skeleton Merchant sells the during Hardmode.

Other effects

 * Deathweed blooms. Blood moons (and Full Moons on ) are the only times you can harvest Deathweed Seeds from Deathweed (with the exception of harvesting with a Staff of Regrowth).
 * Most NPCs have their own unique lines commenting on the event.
 * The Zoologist NPC will transform into her werefox form regardless of the moon phase.
 * Fishing power is 1.1x stronger, and can provide some unique items and spawn unique enemies, including the Dreadnautilus.
 * Visual effects:
 * Almost all water will turn red, including Rain. Exception:  The Ocean will not turn completely red, though it will be affected by the screen filter.
 * A red filter will be applied to the screen as well, shifting the colors of all entities and light towards red and purple shades.
 * This will also affect the projectile colors of many weapons.
 * Placed Living Cursed Fire Blocks turn yellow, making a unique effect.
 * The Glowing Mushroom Biome, which is normally blue, will have the red shader make it appear pink-purple.

Tips

 * During a Blood Moon in Hardmode, every enemy and NPC has a chance of dropping the KO Cannon. This means that even though it is rare, like with the Blessed Apple, the large number of drop chances makes this easier to farm, and the KO Cannon is likely to aid a player in early Hardmode.
 * Simply placing a block in front of a door will prevent Zombies from being able to open the door.
 * If the player sees the notification that a Blood Moon is rising and they are under-equipped to defeat it, they should get underground as quickly as possible. Going indoors will not save them, nor will standing around outside. The Blood Moon gives enemies dangerous abilities, such as the ability to open doors.
 * Although the Blood Moon is typically treated as a deadly event, it is possible to enjoy the event. Once the player has max health and good weapons and armor, the new enemies are not a serious threat, especially if they have prepared their base. As the Tavernkeep says, ""
 * The Blood Moon is a great place to use weapons with the Cursed Inferno debuff. It does significantly increased damage since 1.4.1, and most Blood Moon enemies are fast, meaning you'll be dodging a lot more than in regular gameplay, and making Cursed Inferno (with its damage over time) much more useful.

Trivia

 * In real life, the Moon appears red during a, which is sometimes referred to as a "Blood Moon". As sunlight passes into the shadow through the atmosphere, the Moon is given a red/orange color due to the amount of air the light passes through. This is the same phenomenon that gives sunsets and sunrises such colors.
 * When a real Blood Moon occurred on April 14, 2014, a warning was jokingly announced on the official Terraria forums.
 * The Blood Moon and Underworld share the same track on the.
 * During a Blood Moon, all female NPCs except the Party Girl and the use more irritable or aggressive dialogue than normal. This is a reference to the fact that some women in real life become irritable or aggressive due to . Both the  and the real-world Moon cycle occur approximately every 28 days.
 * Female player characters are not subject to such changes - all dialogue between the player and NPCs is as normal for blood moons and the player is not implied through the NPCs to appear more irritable.
 * The Blood Moon is the only thing in the game with its song title (Eerie) not being named after what it plays for. (e.g. The song that plays at nighttime in the Forest biome is named "Overworld (Night)")