How can a death note shorten the lifespan of others?


**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.**

We saw, that Misas lifespan was shortened because Light was killed by Ryuk. So
this means, that you can shorten a persons lifespan with the death note. So
let's say, A has a death note and knows that C wants to kill B with a death
note. He writes B's name in his death note, thus preventing him from being
killed by a death note. So C, can't kill B with a death note anymore. But
since the death note can shorten the lifespan of those, whos name isn't
written in the death note, C decides to use Y, to set up a trap. C writes:

Y, Car accident. Dies at 12:30, after he produces a deadly poison, which he
injects into the food the person he knows as ''B'' eats. After he did this, he
will die 9 days later in a car accident.

So, could C shorten B's lifespan in this way, so that he is able to indirectly
kill him?




Yes, to the extent of how can you manipulate a person's actions with the DN.
[(1)](https://anime.stackexchange.com/questions/17280/how-long-can-you-
manipulate-a-person-with-a-death-note?rq=1)
[(2)](https://anime.stackexchange.com/questions/7415/can-writing-in-the-death-
note-influence-others?rq=1). But care must be taken not to break the other
rules:

In your example, B will die in at most 23 days because A has written B's name
in his DN.

But let's assume C wants B dead BEFORE that timeframe.

There is a conflict in the writing C did in the DN:

> Y, Car accident. Dies at 12:30, after he produces a deadly poison, which he
> injects into the food the person he knows as ''B'' eats. After he did this,
> he will die 9 days later in a car accident.

C's writing may be in conflict with this rule:

> 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 though only one name is written in the Death Note, if it
> influences and causes other humans that are not written in it to die, the
> victim’s cause of death will be a heart attack

So it can either be considered as a violation of the rule above (and Y will
die of heart attack) or work as intended by C.




Yes, to the extent of how can you manipulate a person's actions with the DN.
[(1)](https://anime.stackexchange.com/questions/17280/how-long-can-you-
manipulate-a-person-with-a-death-note?rq=1)
[(2)](https://anime.stackexchange.com/questions/7415/can-writing-in-the-death-
note-influence-others?rq=1). But care must be taken not to break the other
rules:

In your example, B will die in at most 23 days because A has written B's name
in his DN.

But let's assume C wants B dead BEFORE that timeframe.

There is a conflict in the writing C did in the DN:

> Y, Car accident. Dies at 12:30, after he produces a deadly poison, which he
> injects into the food the person he knows as ''B'' eats. After he did this,
> he will die 9 days later in a car accident.

C's writing may be in conflict with this rule:

> 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 though only one name is written in the Death Note, if it
> influences and causes other humans that are not written in it to die, the
> victim’s cause of death will be a heart attack

So it can either be considered as a violation of the rule above (and Y will
die of heart attack) or work as intended by C.

