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.
After writing the cause of death, the details of the death should be entered within the next six minutes and 40 seconds.
If the tiem of death is specified within 40 seconds after writing the cause of death as a heartattack, 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 for that human or could be reasonably assumed to be carried out by that human.
Since the limitations applying to the conditions of death are unknown to the Shinigami, Death Note owners must find out on their own.
You may 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 cause of death. You have about 19 days (according to the human calender) to fill in a name.
Suicide is a universally valid cause of death as all humans are thought to possess the potential to commit suicide. It is, therefore, something that may be reasonably assumed of an individual.
Wheter the cause of the individual's death is either suidide or an accident, if it would lead to the death of more than the intended victim, the person will simply die of a heart attack. This is to ensure that other lives are not impacted.
After an individual's name, time of death, and conditions of death are entered in the notebook, the time 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 adre 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.
Even if only one name is written in the Death Note, if the victim's death causes other humans that are not written in it to die, the cause of death will default to a heart attack.
If you write "dies rom disease" and specify which disease and the 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 six minutes and 40 seconds after the entry in the Death Note.
If you write "dies from disease" as the cause of death but specify only a time of death and not the actual disease, the victim will die from a plausible disease.
The Death Note can only operate within a 23-day window (in the human calendar). This is called the 23-day rule.
If you write "dies from disease" and specify which disease but not a time of death, if the progression of the disease takes more than 24 days, the 23-day rule will not take effect and the human will die at an appropriate time depending on the disease. However, rewriting the cause and/or details of death must be done within six minutes and 40 seconds: you cannot change the victim's time of death, however soon it may be.
In order for the Death Note to take effect the victim's name must be written on one page; however, the cause and conditions of death may be entered on other pages. This will work as long as the person who writes in the Death Note keeps the specific victim's name in mind when writing the cause and conditions of death.
If the cause and conditions of death are written in before the victim's name is, multiple names can be written as long as they are entered within 40 seconds and the cause and conditions of death are not impossible. In the event that the cause of death is possible but the conditions are not, only the cause of death will take effect for that victim if both the cause and the conditions are impossible, that victim will die of a heart attack.
When you write multiple names in the Death Note and then write down one cause of death within 40 seconds of writing the first victim's name, the cause will take effect for all the written names. Also, after writing the cause of death, even if the conditions of death are written within six minutes and 40 seconds in the human world, the conditions will apply only to the victims for whom they are possible. Those for whom the conditions are not possible will simply die from the specified cause.
A human death caused by the Death Note can indirectly lengthen another human's original life span in the human world even without the owner's specific intention to do so.
Once the victim's name, cause of death, and conditions of death have been written down in the Death Note, the death will take place even if that Death Note, or the part of the note used, is destroyed before the stated time of death.
If the victim's name has been entered and the Death Note is destroyed while the cause of death is being written, the victim will be killed by a heart attack 40 seconds after the name was entered. If the victim's name and cause of death have already been written, then the victim will be killed within six minutes and 40 seconds via the stated cause of death if it is possible within that period of time. Otherwise, the victim will die by heart attack.