Use of the magic missile spell creates up to five missiles of magical energy that dart forth from the wizard's fingertip and unerringly strike their target. This includes enemy creatures in a melee. The target creature must be seen or otherwise detected to be hit, however, so near-total concealment, such as that offered by arrow slits, can render the spell ineffective. Likewise, the caster must be able to identify the target. He cannot direct a magic missile to "Strike the commander of the legion," unless he can single out the commander from the rest of the soldiers. Specific parts of a creature cannot be singled out. Inanimate objects cannot be damaged by the spell.
Note: This version of magic missile originally appeared in the 2nd Edition Player's Handbook for Advanced Dungeons & Dragons from TSR. Its use here is for the purposes of providing context for the campaign only.