[quote=@Lugubrious]
<Snipped quote by harinezumikouken>

I don't think that's necessary.  Mana comes back slowly enough that it can be treated as a finite resource in an engagement.  If someone runs out of mana, it'll be some time (half an hour or more depending on the person) before even a single spell can be used.  Plus, mana consumption makes the user tired in the same way as physical exercise.
[/quote]

Alrighty-rooty.