Grimrock

I right click to use my weapons but left click to fire my spells, this has been responsible for my death on more than one occasion.
It really doesn't seem to make a lot of sense.

I, uh.. don't understand the question.

In the spellcast mode, you can use either the left or right mouse buttons to select/deselect runes and execute the spell.

I noticed the same. basically you right click to open the spell menu, but you left click on the 3x3 icons.

I guess just using right click for clicking on these icons would ease confusion?

Daniel.