If the time of death is written within 40 seconds after writing the cause of death as a heart attack, the time of death can be manipulated, and the time can go into effect within 40 seconds after writing the name.
The human who touches the Death Note can recognize the image and voice of its original owner, a god of death, even if the human is not the owner of the note.
A god of death can extend their own life by putting a name on their own note, but humans cannot.
A person can shorten his/her own life by using the note.
The human who becomes the owner of the Death Note can, in exchange of half his/her remaining life, get the eyeballs of the god of death which will enable him/her to see a human's name and remaining life span when looking through them.
A god of death cannot be killed even if stabbed in his heart with a knife or shot in the head with a gun. However, there are ways to kill a god of death, which are not generally known to the god of death.
You may also write the cause and/or details of death prior to filling in the name of the individual. Be sure to insert the name in front of the written cause of death. You have about 19 days (according to the human calendar) in order to fill in a name.
Even if you do not actually possess the Death Note, the effect will be the same if you can recognize the person and his/her name to place in the blank.
Suicide is a valid cause of death. Basically, all humans are thought to possess the possibility to commit suicide. It is, therefore, not something unbelievable to think of.
Whether the cause of the individual's death is either a suicide or accident, if the death leads to the death of more than the intended, the person will simply die of a heart attack. This is to ensure that other lives are not influenced.
Even after the individual's name, the time of death, and death condition on the Death Note were filled out, the time and condition of death can be altered as many times as you want, as long as it is changed within 6 minutes and 40 seconds from the time it was filled in. But, of course, this is only possible before the victim dies.
Whenever you want to change anything written on the Death Note within 6 minutes and 40 seconds after you wrote, you must first rule out the characters you want to erase with two straight lines.
As you see above, the time and conditions of death can be changed, but once the victim's name has been written, the individual's death can never be avoided.
If you lose the Death Note or have it stolen, you will lose its ownership unless you retrieve it within 490 days.
If you have traded the eye power of a god of death, you will lose the eye power as well as the memory of the Death Note, once you lose its ownership. At the same time, the remaining half of your life will not be restored.
You may lend the Death Note to another person while maintaining its ownership. Subletting it to yet another person is possible, too.
The borrower of the Death Note will not be followed by a god of death. The god of Death always remains with the owner of the Death Note. Also, the borrower cannot trade the eyesight of the god of death.
If the god of death decides to use the Death Note to kill the assassin of an individual he favors, the individual's life will be extended, but the god of death will die.
The dead god of death will disappear, but the Death Note will remain. The ownership of this Death Note is usually carried over to the next god of death that touches it, or is kept in possession of the human owner of the Death Note.
Only by touching each other's Death Note can human individuals who own the Death Note in the human world recognize the appearance or voice of each other's God of Death.
An individual with the eye power of a god of death can tell the name and life span of other humans by looking at that person's face. By possessing the Death Note, an individual gains the ability to kill, and stops being a victim. From this point, a person with the Death Note cannot see the life span of other Death Note owners including him/herself. But, it is not really necessary for the individual to view the life span of him/herself or other Death Note owners.
The god of death must not tell humans the names or life spans of individuals he/she sees. This is to avoid confusion in the human world.
In order to see the names and life spans of humans by using the eye power of the god of death, the owner must look at more than half of that person's face. When looking from top to bottom, he must look at least from the head to the nose. If he looks at only the eyes and under, he will not be able to see the person's name and life span. Also, even though some parts of the face, for example the eyes, nose or mouth are hidden, if he can basically see the whole face, he will be able to see the person's name and life span. It is still not clear how much exposure is needed to tell a person's name and life span, as this needs to be verified.
If above conditions are met, names and life spans can be seen through photos and pictures, no matter how old they are. But this is sometimes influenced by the vividness and size. Also, names and life spans cannot be seen by face drawings, however realistic they may be.
The individuals who lose the ownership of the Death Note will also lose their memory of the usage of the Death Note. This does not mean that he will lose all the memory from the day he owned it to the day he loses possession, but means he will only lose the memory involving the Death Note.
Whenever an individual with ownership of more than two Death Notes loses possession to one of the Death Notes, he will not be able to recognize that Death Note's god of death's appearance or voice anymore. The god of death himself will leave, but all the memory involving that Death Note will remain as long as he maintains ownership of at least one other Death Note.
The god of death must not hand the Death Note directly to a child under 6 years of age based on the human calendar.
The Death Note must not be handed to a child under 6 years of age, but Death Notes that have been dropped into the human world, and are part of the human world, can be used upon humans of any age with the same effect.
If you write "die of disease" with a specific disease's name and the person's time of death, there must be a sufficient amount of time for the disease to progress. If the set time is too tight, the victim will die of a heart attack after 6 minutes and 40 seconds after completing the Death Note.
If you write, die of disease for the cause of death, but only write a specific time of death without the actual name of disease, the human will die from an adequate disease. But the Death Note can only operate within 23 days (in the human calendar). This is called the 23 day rule.
If you write "die of disease" like before with a specific disease's name, but without a specific time, if it takes more than 24 days for the human to die the 23 day rule will not take effect and the human will die at an adequate time depending on the disease.
When rewriting the cause and/or details of death it must be done within 6 minutes and 40 seconds. You cannot change the victim's time of death, however soon it may be.
If someone possesses more than one Death Note, by visualizing the victim, then writing down the name in one of the Death Notes and the cause of death in the other, it will take effect. The order however, is unimportant, if you write down the cause of death in one Death Note and afterwards, write the name in the other, it will take effect.
This can also be accomplished by two Death Note owners working together. In this case, it's necessary that the two touch each other's Death Notes.
If a person loses possession of a Death Note, they will not recognize the gods of death by sight or voice any more. If however, the owner lets someone else touch his Death Note, from that time on, that person will recognize the god of death.
In accordance with the above, the human who touched the Death Note and began to recognize the gods of death's image and voice, will continue to recognize it until that human actually owns the Death Note and subsequently loses possession of it.
If a Death Note owner accidentally misspells a name four times, that person will be free from being killed by the Death Note. However, if they intentionally misspell the name four times, the Death Note owner will die.
The person whose name was misspelled four times on purpose will not be free of death by a Death Note.
Note about the numbering: The Japanese edition reuses numbers XLII (42) and XLIII (43) between volumes 7 and 8. Viz cut two rules in Volume 7, and renumbered the rules they kept, beginning with rule XXXIX (39). The rules between the Japanese and Viz editions correspond again in volume 8.
When regaining ownership of the Death Note, the memories associated with the Death Note will also return. In cases where you were involved with other Death Notes as a well, memories of all the Death Notes involved will return.
Even without obtaining ownership, memories will return just by touching the Death Note.
You will lose memory of the Death Note when losing its ownership. But you can regain this memory by either obtaining the ownership once again or by touching the Death Note. This can be done up to 6 times per Death Note.
If the 6 times are exceeded, the person's memory of the Death Note will not return and they will have to use it without any previous memory of it.
Humans that have traded for the eye power of a god of death will see a person's primary life span, and will not be influenced by the Death Note. If the victim is killed using the Death Note, the remaining lifetime of that victim will be provided to the god of death.
Note: This rule is not included in the Viz version. Viz uses this number for a different rule.
The use of the Death Note in the human world sometimes affects other humans' lives or shortens their original life span, even though their names are not actually written in the Death Note itself. In these cases, no matter the cause, the god of death sees only the original lifespan and not the shortened lifespan.
Note: This number is duplicated in the Japanese version of volume 7.
If the Death Note that the god of death owns is taken away by being cheated by other gods of death and so forth, it can only be retrieved from the god of death who possesses it at the time. If there is no god of death, but a human possessing it, the only way that the god of death can retrieve it will be to first touch the Death Note and become the god of death that haunts that human. Then wait until that human dies to take it away before any other human touches it, or whenever the human shows a will to let go of it.
There are laws in the world of gods of death. If a god of death should break the law, there are 9 levels of severity starting at Level 8 and going up to Level 1 plus the Extreme Level. For severity levels above 3 the god of death will be killed after being punished.
For example, killing a human without using the Death Note is considered as the Extreme Level.
Losing memory of the Death Note by passing on the ownership to another, or by abandoning its ownership will only occur when someone is actually killed using that Death Note. You will not lose memory of the Death Note, for example, if you merely owned it and had not written anyone's name. In this case, you will not be able to hear the voice or see the figure of the god of death any more. You will also lose the eye power of the god of death you traded with.
How to Use It: XLVIII
The god of death will not die from lack of sleep. Moreover, gods of death do not really need sleep. The meaning of sleep for gods of death is essentially different from humans and is merely laziness.
Especially gods of death living in the human world that have passed on their Death Note shouldn't be lazy, as they are required to see the death of the human, but it is not that they are not allowed to sleep.
How to Use It: XLIX
Only 6 Death Notes are allowed to exist at a time in the human world. Of course, the Death Note that the god of death owns does not count. This means only 6 gods of death that have passed on their Death Note to humans can stay in the human world.
How to Use It: L
One god of death is allowed to pass on Death Notes to only 3 humans at a time.
It is possible for a single god of death to hand out up to 6 Death Notes, for example, by handing 3 humans 2 Death Notes each.
In other words, one human could own all 6 Death Notes.
How to Use It: LI
However, if a seventh Death Note is owned by a human in the human world, nothing will happen even if used.
The Death Note will not take effect if you write a specific victims name using several different pages.
But the front and back of a page is considered as one page. For example, the Death Note will still take effect if you write the victim's surname on the front page and given name on the back.
How to Use It: LIV
In order to make the Death Note take effect, the victim's name must be written on the same page, but the cause of death and situation around the death can be described in other pages of Death Note. This will work as long as the person that writes in the Death Note keeps the specific victims name in mind when writing the cause and situation of death.
How to Use It: LV
In occasions where the cause and situation of death is written before the victim's name, multiple names can be written as long as they are written within 40 seconds and the causes and situations of death are not impossible to occur.
In the occasion where the cause of death is possible but the situation is not, only the cause of death will take effect for that victim. If both the cause and the situation are impossible, that victim will die of heart attack.
How to Use It: LVI
When you write multiple names in the Death Note and then write down even one cause of death within 40 human seconds from writing the first victims name, the cause will take effect for all the written names.
Also, after writing the cause of death, even if the situation of death is written within 6 minutes and 40 seconds in the human world, the situation will only occur to the victims whom it is possible. For those where the situation is not possible, only the cause of death will occur.
How to Use It: LVII
In the Death Note, you cannot set the death date longer than the victim's original life span. Even if the victim's death is set in the Death Note beyond his/her original life span, the victim will die before the set time.
How to Use It: LVIII
By manipulating the death of a human that has influence over another human's life, that human's original life span can sometimes be lengthened.
If a god of death intentionally does the above manipulation to effectively lengthen a human's life span, the god of death will die, but even if a human does the same, the human will not die.
A human death caused by the Death Note will indirectly lengthen some other human's original life even without a specific intention to lengthen a particular person's original life span in the human world.
After a god of death has brought the Death Note to the human world and given its ownership to a human, that god of death has the right to kill the human using his/her own Death Note for reasons such as disliking the owner.
How to Use It: LXI
Even if a new victim's name, cause of death, or situation of death is written on top of the originally written name, cause of death or situation of death, there will be no effect on the original victim's death. The same thing will also apply to erasing what was written with a pencil, or whitening out what was written with a pen, in attempt to rewrite it.
Once the victim's name, cause of death and situation of death have been written down in the Death Note, this death will still take place even if that Death Note or the part of the note in which it has been written is destroyed, for example, burned into ashes, before the stated time of death.
If the victim's name has been written and then the Death Note is destroyed in the middle of writing the cause of death, the victim will be killed by heart attack in 40 seconds after writing the name.
If the victim's name and cause of death have been written and the middle of writing the situation of death, then the victim will be killed within 6 minutes and 40 seconds via the stated cause of death if the cause is possible within that period of time, but otherwise, the victim will die by heart attack.
No matter what medical or scientific method may be employed, it is impossible for humans to distinguish whether or not the human has the eye of power of a god of death. Even gods of death cannot distinguish this fact, except for the very god of death that traded his/her eye power with that human.
The following situations are the cases where a god of death that has brought the Death Note into the human world is allowed to return to the world of gods of death.
When the god of death has seen the end of the first owner of the Death Note brought into the human world and has written that human's name on his/her own Death Note.
When the Death Note which has been brought in is destroyed, like burned, and cannot be used by humans anymore.
If nobody claims the ownership of the Death Note, and it is unnecessary to haunt anyone.
If, for any reason, the god of death possessing the Death Note has been replaced by another god of death.
When the god of death loses track of the Death Note which he/she possesses, cannot identify which human is owning the Death Note, or cannot locate where the owner is, and therefore needs to find such information through the hole in the world of gods of death.
Even in the situations 2, 3, and 4 above, gods of death are obliged to confirm the death of the first owner and write down that human's name in his/her Death Note even when he/she is in the world of gods of death.
In the world of gods of death there are a few copies of what humans may call user guidebook for using the Death Note in the human world. However, the guidebook is not allowed to be delivered to humans.
It is perfectly okay for gods of death to read the guidebook for him/herself and teach humans about its contents, no matter what the content may be.