Steve Jackson Games Forums - View Single Post - [Powers] Are Multiplicative Modifiers Fairer?

Seneschal · 08-24-2019, 03:17 AM

Hmm, I realized from the last few posts that I don't remember how GURPS multiplicative modifiers work - I had assumed they were calculated like in the HERO System, where:

Enhanced cost = base cost x (1 + enhancements)

Limited cost = enhanced cost ÷ (1 + limitations)

That way, there's no need to have an 80% maximum on limitations. However, modifiers also come in chunks of ±¼ in HERO, so you end up with an enhancement total of "+3" or a limitation total of "-2½", which is easier to plug into that formula.

Anyway, given the flexibility of GURPS modifiers, a GM serious about maintaining balance should do more than just set a CP total and check if powers are "legal" - it's also important to sets a range for traits and modifiers allowed in the campaign. Much like a realistic setting sets a "human maximum" for attributes, a GM could forbid powers that have a base cost above 50 pts, have more than +150% worth of enhancements, or more than two limitations, or veto specific combinations of modifiers. As was pointed out already, you can make a universe-destroying attack for cheap even with additive modifiers; it's the GM's job to spot such abuses (and it's the player's job to not be a jerk about it).

08-24-2019, 03:17 AM	#17
Seneschal Join Date: Jul 2009	Re: [Powers] Are Multiplicative Modifiers Fairer? Hmm, I realized from the last few posts that I don't remember how GURPS multiplicative modifiers work - I had assumed they were calculated like in the HERO System, where: Enhanced cost = base cost x (1 + enhancements) Limited cost = enhanced cost ÷ (1 + limitations) That way, there's no need to have an 80% maximum on limitations. However, modifiers also come in chunks of ±¼ in HERO, so you end up with an enhancement total of "+3" or a limitation total of "-2½", which is easier to plug into that formula. Anyway, given the flexibility of GURPS modifiers, a GM serious about maintaining balance should do more than just set a CP total and check if powers are "legal" - it's also important to sets a range for traits and modifiers allowed in the campaign. Much like a realistic setting sets a "human maximum" for attributes, a GM could forbid powers that have a base cost above 50 pts, have more than +150% worth of enhancements, or more than two limitations, or veto specific combinations of modifiers. As was pointed out already, you can make a universe-destroying attack for cheap even with additive modifiers; it's the GM's job to spot such abuses (and it's the player's job to not be a jerk about it).