I'm in search of game balance advice. In the description for M4@8 Manipulate Magic, it says that if the spell targets magic and there is still a magical effect after the spell succeeds, it's a skill under that heading. It gives suggested baselines for an array of uses, but it doesn't address a spell whose purpose is merely to extend the duration of another effect already in progress. Ordinarily, I'd just eyeball it, but this struck me as something with some serious potential for imbalace. (Let's see, I'll take a +20 sit-mod on the three-hour climate control for cutting the duration down to 7:30:00, then I'll cast my guaranteed-success three-minute Extend Duration spell - that's +40 for the time factor - and I'll do that five times for +RS% to the duration each time . . .)
So, I guess I'm looking for opinions in three areas:
1) What should the baseline time factor be? Most M4@8 Manipulate Magic skills run about twelve seconds, but I think this one's atypical. The standard one-to-ten TF-to-duration rule of thumb isn't much help here either.
2) How should the length of the extension be determined - based on the TF of the target skill, based on the TF of the extension skill, or fixed somehow and thus relative to neither?
3) How narrowly, at baseline, should such skills be defined? This could range from, at one extreme, a single Extend Duration skill for any in-place magical effect to, at the other, a separate skill for each specific spell the caster would like to be able to extend. What should be the standard, and what should be craziness calling for ad-hod adjustments to the other baseline values?
