Cutting fireballs in half

A small addition to a recent post.

As people noticed in the comments, it is not such a huge deal. But a random idea came to mind.

What if we just cut everything by half? Say, magic-users have a "Sorcery" skill that is half their level, round up (clerics use 1/3 level, round to nearest integer).

With sorcery 3, you can cast level 3 spells. Also, fireball does 1d6 damage per sorcery level. In B/X, this would mean 7d6 at most, but up to 10d6 in AD&D.

Now, to replace spell slots, just roll 1d20, add your sorcery level (and maybe INT), subtract spell level. 20 or more means you get to keep the spell. 

Or use spell points.

Magic-missile follow a similar pattern; you can throw three at once only when you get level 6 spells (3d6+3 with no saves and ignoring armor is not bad).

MAYBE you can choose to "upcast" by dealing maximum damage and losing the spell automatically, which adds a risk-reward aspect and allows you to cast fireball with its former glory once a day.

This makes magic-users weaker. To compensate, they use fighter XP table and can use any weapon and armor.

This doesn't really "solve" D&D magic but would allow to give old school games a stronger S&S feel - fireballs are less impressive, charm and sleep are still powerful, and wizards rely on swords often.

BTW: maybe the same goes for dragons. 10 HD means 5d6 breath. So PCs have a fighting chance - even if you give them more HD.

Anyway, just a random thought for now.