Death Note (object)

A Death Note is a supernatural notebook which is used by Shinigami to sustain their life.

Overview
The purpose of the Death Note is to take Human life, thereby increasing the life of the Shinigami who uses it. There are many rules as to how the Death Note can be used, though the most pivotal rule is that "The Human whose name is written in this note shall die."

Use By Shinigami
Shinigami normally use Death Notes to kill humans from the Shinigami Realm, thereby adding each human's remaining years of life to their own. Rogue Shinigami are Shinigami who drop extra Death Note(s) from the Shinigami Realm down to the human world in order to allow humans the use of their spare killer notebook(s). It is unknown how many notebooks exist in the Shinigami Realm, as well as how Death Notes are created.

Use By Humans
A Death Note can be used by a human, although their lifespans do not increase by doing so. Historically, humans have either killed other humans with the Death Note(s) or ended up burning and therefore destroying the Death Note for any number of reasons. Ryuk is the first Rogue Shinigami that is shown in the manga, yet it is stated early in the series that there have been other Death Notes dropped in the human world before.

Death Notes
A total of four notebooks are present in the Human World during the series. These notebooks are listed here along with names of the people who gained ownership. In this article the notebooks are referred to using the name of the Shinigami who originally owned it. For example, the first notebook used by Light is called "Sidoh's Death Note".

Sidoh's Death Note
Ownership passes from: Sidoh, to Ryuk, to Light Yagami, to Ryuk, to Rem, to Kyosuke Higuchi, to Jack Neylon, to Light Yagami, to Sidoh.

Gelus's Death Note
Ownership passes from: Gelus, to Rem, to Misa Amane, to Teru Mikami.

Rem's Death Note
Ownership passes from: Rem, to Light Yagami, to Soichiro Yagami, to Light Yagami.

Ryuk's Death Note
Ryuk's notebook remains with him for the entirety of the series. It is not used until the very end, when he writes down the name of Light Yagami.

Ownership passes: None.

How to Use It: The Complete Rules
'The following information is quoted directly from Death Note: How To Read 13. Please note that this is not a list of the rules written in the Death Note by Ryuk. For that, see Sidoh's Death Note. For a complete list of Rules governing use of the Death Note, see The Rules of the Death Note.'

'''This section reveals the rules governing the use of the Death Note. They have been divided into four parts: How to Use It, Ownership, the Shinigami Eyes, and the Shinigami Rules. Here the rules will be explained by highliting specific scenes from the series.'''

1.1 Entering Names

 * The Human whose name is written in this note shall die. This note will not take effect unless the writer has the subjects face in mind when writing his/her name. This is to prevent people who share the same name from being affected. Use in the story: Realizing that people sharing the same name cannot be killed at once, L uses the name of an idol singer named Hideki Ryuga and approches Light.
 * The Death Note will not ever affect a person whose name has been misspelled four times.
 * When the same name is written in two or more Death Notes within 0.06 seconds, the entry is regarded as simultaneous; the Death Notes will not take effect and the individual will not die.
 * When the same name is written in two our more Death Notes, the note which was used first will take affect, regardless of the time of death.
 * If a Death Note owner accidently misspells a person's name four times, that person will be free from being killed by the Death Note. However, if the Death Note owner intentionally misspells the name four times, the owner will die.
 * The Death Note will not take effect if the victim's name is written on several different pages. However, the front and back of a page is considered to be one page. For example, the Death Note will take effect if the victims's last name is written on the front page and first name on the back.

1.2 Entering the Causes and Conditions of Death

 * If the cause of death is written within 40 seconds of the subject's name, it will happen.
 * If the cause of death is not specified, the subject will die of a heart attack. If the cause of death isn't specified, the victim dies of a heart attack in 40 seconds. However, the rule can be delayed for twenty-three days, meaning you can write down "dies by heart attack in [xx] days."
 * After writing the cause of death, the details of the death should be entered within the next 6 minutes and 40 seconds.
 * If the time of death is specified within 40 seconds after writing the cause of death as a heart attack, the time of death can be manipulated and can go into effect within 40 seconds after writing the name.
 * The conditions of death will not be realized unless they are physically possible for that human of could be reasonably assumed to be carried out by that human. Although it is possible to control a person's actions, if an impossible situation is written down the person will die of a heart attack.
 * Since the limitations applying to the conditions of a death are unknown to the Shinigami, Death Note owners must find out on their own.
 * You may write the cause and/or death prior to filling in the name of the individual. Be sure to insert the name in front of the cause of death. You have about 19 days (according to the human calendar) to fill in a name. Use in the story: Light was able to wipe out all the FBI agents by writing their conditions of death ahead of time and having Raye write in the names.
 * After an individual's name, time of death, and conditions of death are entered in the notebook, the fime and conditions of death may be altered as many times as desired as long as they are changed within six minutes and 40 seconds from the time they are filled in. But, of course, this is only possible before the victim dies.
 * If you write "dies of accident" for the cause of death, the victim will die from a natural accident six minutes and 40 seconds after the time of entry. "Accident" is a condition of death, so six minutes and 40 seconds are provided to write down additional details. The conditions do not take effect until this time has passed.

Appearance
The inside of a notebook looks like that of a school notebook, and contains ruled white pages. The notebook is activated when someones name is written in it. Regardless of how many names are written in it, the notebook will never run out of pages. Death Notes are made from an unknown material, however they feel and look like regular notebooks and it is possible to rip or burn the pages. Human science cannot analyze a Death Note.

There are several different Death Note designs. The appearance of a Death Note is chosen by the Shinigami. Most Death Note's are plain black (such as Rem's) and do not have writing on the cover, however Shinigami sometimes write their name on it or the words "Death Note". Those that do contain writing on the front can have the words written in any language, such as English (Sidoh's Death Note) or a Shinigami language (Gelus's Death Note). Other cover designs may exist as well, but that would be completely up to the Shinigami owning that particular Death Note. Death Notes which are red or white exist, although they are never shown in the series. Death Note's can also take a form other than a notebook, such as a scroll. Death Note: How To Read 13 suggests that the form changes based on the human era.

Trivia
Shonen Jump also made Death Note notebook replicas which can be bought from their website, and Misa's Death Note for the Death Note movie is also purchasable, which comes with a pen.