How does Rasengan do so less damage?


When Jiraiya used Rasengan on a tree, it shredded part of it and trees are not
soft. They are so much harder than human flesh. However, the first time
Jiraiya used it on a gangster, he didn't die.

Why is that? He should have been torn to shreds.




When the [Rasengan](http://naruto.wikia.com/wiki/Rasengan) makes impact, there
are two effects that take place

The first effect is

> On contact, the Rasengan grinds into its target, propels them along the
> Rasengan's trajectory - either away from the user or into the ground beneath
> them

When Jiraiya used the Rasengan against the gangsters, this what we saw.

The second effect is

> and at some point bursts, causing severe damage at the point of contact.

The burst is what truly deals the damage. Jiraiya mastered the technique of
the Rasengan and more than likely had control over it for it to not burst.

Anyways, he was trying to make a point and get the gangsters off of his back -
there was no need to kill them. [Jiraiya even
says](https://youtu.be/Zr3PFfh3Uw4?t=60)

> And I was holding back. You guys are hardly worth the trouble

