proposed new rule: The maximum casting time one can make a spell is x*2n+1 rounds, where x is the minimum (cheese-less) level one must be to cast the spell, and n is the minimum (cheese-less) level one can cast the spell at. For example, a third level spell can take a maximum of 5*(2^4) rounds, or 8 minutes, a ninth level spell can take a maximum of 17*(2^9) rounds, or about 29 hours. First level spells can take a maximum of four rounds, and a cantrip counts as a spell level of 1/2 for this, yielding a single round. Does this sound fair as a guideline? It invalidates several of the previous spells, but it's only a guideline.