New Advantages

The GM (no doubt with the enthusiastic advice of the players!) is free to add as many new advantages as he can think of. What follows are some guidelines on how to balance the costs of such advantages in light of the traits in this chapter.

Players take note: these rules are for GMs. You may invent new advantages only with the GM's permission.

Modifying Existing Advantages

GURPS has a lot of advantages. Often, one of these is similar to what you had in mind, in which case you can "tweak" an existing ability instead of inventing a new one.

Rename

The advantage you're looking for might already exist, but under a moniker you dislike or find unintuitive. In this case, creating a "new" advantage is just a matter of changing the name! For instance, if you want a Light Intensification advantage that lets those who have it see in the dark, just rename "Night Vision" to "Light Intensification."

Redefine

Many "new" advantages amount to existing advantages with revised special effects. If an existing advantage provides the right ability with the wrong justification, use the game mechanics and point cost of the existing trait but come up with a new explanation for how it works. For instance, Night Vision assumes natural, dark-adapted eyes, but you are free to explain it as ultra-tech implants, if that suits your campaign better.

Combine

Still other "new" advantages are combinations of existing traits. If a mix of advantages (possibly with a few disadvantages, to bring the cost down) collectively provide the effects you want, just group them together, add their costs, and rename the whole thing.

For instance, you might lump together Acute Vision 5 [10], Night Vision 5 [5], and Colorblindness [-10] as the "Cat’s Eye Mk. V" implant. Players would just list "Cat’s Eye Mk. V [5]" on their character sheet.

Note that this is identical to the way meta-traits work.

Modify

The game mechanics for an existing advantage will sometimes be almost, but not quite, what you want. In that case, start with the nearest existing advantage, apply enhancements and limitations that add the desired effects, and present the final product as an entirely new advantage.

For instance, suppose undead beings in your campaign can see the Spectral Plane. This gives them Night Vision with the side effects that they see ghosts and have glowing red eyes. You could write this as "Night Vision 5 (Affects Insubstantial, +20%; Temporary Disadvantage: Unnatural Feature, -5%) [6]," but it would be simpler to write "Spectral Vision [6]" on character sheets and leave the design details in your notes.

Fine-Tune

After applying the above processes to achieve the effects you seek, you might wish to add some "color" or adjust the cost – perhaps by adding minor side effects, such as small modifiers to certain success rolls. The guidelines and examples under Perks and Quirks can be useful here.

For instance, you might want "Spectral Vision" to cost a nice, round 5 points, but you don't want to make the ability to see ghosts a freebie. To justify shaving the cost down to 5 points, you toss in a -1 to Vision rolls made in bright daylight. After all, everyone knows the undead don't like sunlight!

Designing Entirely New Advantages

There are times when nothing less than a totally new advantage will do. Advantages in GURPS usually grant one of four basic types of abilities (although a single advantage often qualifies in more than one category).

1. Situational bonuses to attributes. Handle attribute bonuses by assuming that each +1 is worth 10 points for ST or HT, or 20 points for DX or IQ, and then modifying the cost downward to reflect how often the bonus applies. See Accessibility for inspiration. For instance, Rapid Healing is basically +5 HT (base cost 50 points) that only applies to rolls to recover from damage. Since most people go to great pains to avoid damage, and since rolls for natural recovery rarely matter in settings with magical, psionic, or ultra-tech healing, the point value of the bonus is reduced to 1/10 of normal, for a net cost of 5 points.
2. Bonuses to skill rolls. In general, simply work out the equivalent Talent and add its cost to the advantage. If the advantage modifies one skill, then assume it is worth 2 points per +1 to skill, to a maximum of +3 to skill for 6 points.
3. Bonuses to reaction rolls. Work out reaction bonuses as described for Reputation. You may include a bonus that applies to a very small class of people (e.g., "anyone with a Ph.D. in Comparative Anatomy from Harvard," unless the campaign happens to be set at Harvard Medical School) for free as a "special effect." Note that these bonuses need not be actual Reputations – they could as easily be due to looks, a psionic aura, or mind-control lasers.
4. Unique abilities that those without the advantage do not have in any measure. You should price these abilities by comparison. Examine other traits in the rules and assign a similar cost for an advantage that is about equal in power. Reduce or increase the cost if the ability is slightly more or less powerful than the one to which you are comparing it. For instance, "automatically makes all normal Vision rolls" is about as useful as "automatically makes all Fright Checks," so you might price that ability along the lines of Unfazeable, for 15 points.

Finalizing the Cost

To determine the final cost of a new advantage, add up the costs of all the abilities it grants. If the advantage is extremely rare, and those who have it could reliably use it as a surprise tactic or as a means of making money, increase its final cost by up to 100%. Conversely, if the GM wants it to be extremely common, he may reduce its final cost by as much as 50%. Use fine-tuning (above) to further adjust the cost.

The GM is the final arbiter when it comes to the cost of new advantages. He is free to charge an Unusual Background – over and above the cost of the advantage – for any new advantage he wishes to restrict to a certain class of characters. This is in addition to any "built-in" rarity modifier.