FX Modifiers
From D20advanced
FX modifiers enhance or weaken FX in various ways, sometimes significantly changing how they work.
Applying Modifiers
Modifiers are permanent changes to how FX work. Positive modifiers, called extras, increase an FX’s cost per rank by 1. Negative modifiers, called flaws, reduce an FX’s cost per rank by 1. To determine the final cost, add the FX’s base cost per rank, plus the total positive modifiers, minus the total negative modifiers. If the result is a positive number, that’s the FX’s new cost per rank. So an FX costing 2 points per rank with modifiers of +3 and –1 has a final cost per rank of 4 points (2 + 3 – 1 = 4).
Fractional FX Cost
If modifiers reduce an FX’s cost to less than 1 power point per rank, each additional –1 modifier beyond that adds to the number of ranks you get by spending 1 character point on a 1-to-1 basis. So 1-point FX with a –1 modifier, rather than dropping to a cost of 0 points per rank instead gets 2 ranks for 1 character point.
An FX’s cost can be expressed as the ratio of character points per rank (PP:R). So an FX costing 3 character points per rank is 3:1. If that FX has a total of –2 in modifiers, it costs 1:1, or 1 character point per rank. Applying another –1 modifier adds to the second part of the ratio, making it 1:2, or 1 character point per two ranks, and so forth.
Continue the progression for further reductions. Gamemasters may wish to limit the final modified cost ratio of any FX in the campaign (to 1:1, 1:2, 1:4, or whatever figure is appropriate). As a general rule, 1:5 (five FX ranks per power point) should be the lowest modified cost for an FX in d20 Advanced, but the GM sets the limit (if any).
Partial Modifiers
You can apply a modifier to only some of an FX’s ranks and not others in order to fine-tune the FX. A modifier must apply to at least one rank, and may apply to as many ranks as the FX has. The change in cost and FX applies only to the ranks with the modifier; the unmodified ranks have their normal cost and FX.
