Ok, so let's say you're level 3, nobody has a magic weapon, and you encounter a shadow.
* you have initiative, because you're a wizard and you always have initiative. You cast magic missile for 7 damages.
* the shadow is very confuse, because it's the very first time it takes damages.
* you use your pearl of power to get your magice missile back.
* the shadow asks itself what to do.
* you cast magic missile again for 7 damages.
The shadow dies, having only 19 hp and you have done 21.
Or, the battle goes.
R1 Cast Magic weapon. the fighter misses (50% miss) and takes 3 str damage.
R2 The fighter hits, half damage is 10 pt, and takes 4 str damge.
R3. The fighter misses, and takes 3 str damage.
r4 the fighter misses due to poor str. the shadow misses
r.5 the fighter hits, but does only 5 pts, and takes 4 str damg
r.6 the fighter misses due to poor str. the shadow misses
R7 The fighter misses, and takes 3 str damage.
R8 the fighter misses due to poor str. the shadow misses
R9 the fighter misses due to poor str and takes 4 str damage, and is now a shadow.
But actually the best version is
R1- cast magic weapon
r2-3. cast magic missile