Melf's Minute Meteors

This spell is unusual in two respects. First, the dweomer enables the caster to cast small globes of fire, each of which bursts into a 1 ft. diameter sphere upon impact, inflicting 1-4 points of damage upon the target creature—or otherwise igniting combustible materials (even solid planks). 

These meteors are missile weapons thrown by the mage, with misses being treated as grenade-like missiles. 

This ability continues from round to round until the caster has fired off as many of these "meteors" as he or she has levels of experience, until he or she decides to forego casting any additional missiles still remaining, or until a dispel magic spell is successfully cast upon the magic-user. 

Second, once Melf's Minute Meteors is cast, the magic-user has the option to discharge the available missiles at the rate of 1 every 2 segments, as desired, or 1 every round (beginning with the initial round of casting). The magic-user may not switch between these options once one of them is chosen.

In the first option, the caster must point at the desired target on the second segment after the spell is cast, and a missile will be discharged. This process is repeated every 2 segments thereafter until all of the missiles are so released. Naturally, this usually will mean that the spell actually carries over into at least the following round.

If the second option is chosen, the magic-user can withhold or discharge missiles as he or she sees fit, so long as one missile is let go during each subsequent round. This option has the benefit of enabling the spell caster to actually discharge one of the "meteors" and conjure some other spell as well in the same round. The other spell must be of such a nature as to not require the continuing concentration of the spell caster, or else he or she will involuntarily forego the casting of any further missiles from the original spell. However, the magic-user's opportunity to discharge a missile and cast a spell in the same round is of such benefit that the potential loss is not of concern.

If the magic-user fails to maintain an exact mental count of the number of missiles remaining, this is an unfailing indication that he or she has involuntarily foregone the remaining portion of the spell.

The components necessary for the casting of this dweomer are nitre and sulphur formed into a bead by the admixture of pine tar, and a small hollow tube of minute proportion, fashioned from gold. The tube costs no less than 1,000 gp to construct, so fine is its workmanship and magical engraving, but it remains potent throughout numerous castings of the spell—unless damaged by accident or abuse.