One of the most common criticisms of GURPS is that it has too many skills. It is hard to argue against this with the huge number of skills found is Basic Set. Then there is skills that require specialization which can make some character types need dozens of skills.
Some folks find Wildcard skills a good solution to reduce the number of skills needed and simplify the game, but I've never liked Wildcards skills. Some are "job" or class based skills that are not always clear what skills they cover (For example, guess what Barbarian! covers. Did you guess any combat skills? Well, you're wrong it has none.) Other wildcards are "category" skills that cover a group of skills that you can guess at. I prefer this second type, but find that the very hard skill cost x3 tends to make these skills super expensive, especially when many of the skills covered default to each other.
I've been playing around with an idea I like to call Skill+, or "Skill Plus". A Skill+ skill that covers a group of skills that are closely related and default to each other. Let's say for example Sword+ would cover Broadsword, Force Sword, Rapier, Saber, Shortsword, Two-Handed Sword, and the Art and Sport versions of these skills too.
Now I could have just made a Wildcard skill called Sword!, but this would make a very expensive skill vs. just buying up one skill and relying on defaults for the rest. Since most of the sword skills default to each other at -4 or less, these means that for 16 points (4 levels at max cost of 4 CP) or less, the player could increase all these skills (with one being four levels higher). But instead of finding the most common default and buying that up high, why not just have all the skills "default" from a meta-skill ... that is what Skill+ is about.
But what should the default be? Since this skill is designed for all the other skills to default from it, I think the most fair thing is to use half the average cross skill default. So sword skills would default from this skill at -2. But since the main skill has no use, why not just have the -2 built in... or bought off?
At first I thought to just advance the skill by two difficulty levels. In this case making an average skill into a very hard one, and give the skill the -2 built in. But, this may cause problems with Hard and Very Hard skills.
The other option, and the one I am leaning towards is to front load the cost of "buying up from default." Skill level cost caps at 4 points, so two levels are 8. So here is how the skill cost progression works:
Sword+, DX/A, Starting at Att-1 for 9, then 10, 12, 16, etc. (level cost + default buy up of two levels for 8 points).
I think this system works well as something between the standard skill list and Wildcard skills. If I find the time, I'll go through the skill list and create a list of skills+.