Basically it puts you in a position of deciding (at least implicitly) to kill something when you don't have to.
Whowhat?
The first step to implicitly not killing things is to implicitly not stick your sword into it.
Thats just the rule! Its like the A-team, just becuase you are shooting automatic weapons does not mean someone has to get hurt...
But how exactly is that rule implicitly forcing you to kill things?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.