GURPS Power-Ups 10: Skill Trees

[KarlKost]

I would like to use this system for RPM which is my favorite magic system (I just can't stand spell lists)

[dataweaver]

RPM doesn't benefit much from Skill Trees, precisely because it doesn't do spell lists.

[Varyon]

Yeah, RPM is pretty invested in the current skill system, and in a way that it probably wouldn't work well for the PU10 treatment, at least not without modifying it quite a bit. It seems like all the Paths plus Thaumatology would be a single Trunk, and as you need to invest as much in Thaumatology as you do any Path, plus the fact that you pretty much always want Path of Magic tied with your highest, you'd exclusively be buying up the Trunk. Heck, even if you only wanted two skills - Thaumatology and your Path of choice - you'd only save [1]/level by buying them as Branches instead of a Trunk. So you'd wind up with all your mages being generalists, with only things like Ritual Mastery and their individual Grimoires distinguishing them mechanically, rather than having many who specialize in particular Paths.

Now, if you modified it so that, say, Thaumatology is its own Branch (possibly off a Trunk that includes Occultism and other related "knowledge" skills), then each Path is its own Trunk - possibly with the effects (Sense, Strengthen, Destroy, Create, Control, Transform) being either Branches or Twigs - then you may be cooking with gas. But that's a fairly significant departure IMO, and you'll wind up with much higher costs (even above what PU10 typically causes) for your mages. But it could be an option.

[TravellingRobot]

I really really like the ideas in here!

Although I'm still wondering whether the costs are maybe too high if you expect the game to be relatively low-powered.

One thing I'm thinking about is this:
Most rolls will be at -5 per default. Why not just lower all attributes by -5 then? Seems like computing the effective skill will be faster in most cases - just add up your attribute and skill tree bonus. You'd only need a simple "attribute rolls without skill get+5".

[dataweaver]

If the only thing that attributes did was to provide a base for skills, that could work. But they don't. See PU9 for a detailed examination of what each attribute provides.

[TravellingRobot]

That is true, you would have to adjust the non-skill part of course. Speed would become (10+DX+HT)/4, HP becomes ST+5, etc.

But right now with skill trees to me it seems you either have to introduce an adjustment to effective skill level (-5 for everything) or make an equivalent adjustment for attributes.

For people already familiar with GURPS suddenly changing all the attribute scores might be jarring and an extra -5 modifier for skill rolls might not be that confusing.

For new players, however, it might be more intuitive and faster if you can just say "for skill rolls you need to roll under attribute+skill bonus". If you have nothing to unlearn, it doesn't really matter if average DX is 5 or 10. Some formulas for secondary attributes need to be adjusted, but an extra +5 or whatever in the formula isn't really that bad. And you'll compute it before play, not during.

[binn05]

I read half of the posts here (I will read the rest later), so forgive me if I repeat what others said.

I experimented with DFRPG skills using the Barbarian template, since one of my players is currently playing one.

Analyzes 1 (Basic Penalty -0).

Barbarians have:

• 23 points spent in a maximum of 4 melee skills.
• 4 points into 1 ranged weapon.
• 14 points in 11 outdoor/exploration skills plus 20 from the Outdoorsman Talent.
• 9 more points in Intimidation, Running, Stealth, and 4 skills to choose from a small list.
• Total 50 + 20 from Talent.

We could do something like this:

Melee Combat 1 [7]

Weapon X 2 [6]

Shield 2 [6]

With DX 13, we get a skill level of 16 for Shield and Weapon of choice, and 14 for everything else.

Shield and weapon got the same skill levels, all other melee combat skills got DX+1, also our Barbarian now has access to a plethora of combat skills he hadn't before at 14.

Ranged Combat 1 [7]
His skill level is 14, the same as for the DFRPG template, but instead of knowing how to use 1 ranged weapon, he now knows all of them.

Outdoor/Exploration 2 [14]
Skills levels: 12 for IQ-based, 15 for HT-based, and 14 for Per-based.
The original template was 10/12 for IQ-based, 12/13 for HT-based, and 13/14 for Per-based.

Social 0 [0]

Intimidation 1 [3]

Now 11, before 10.

Athletics 0 [0]

Running 1 [3]

Now 14, before 12

Sneakiness 0 [0]

Stealth 1 [3]

Now 14, before 13.

The last 4 skills are from Animal, Athletics, Medical, Military/Reconnaissance, Social, Theft, and Seamanship I couldn't find in any trunk.
I don't think a Barbarian should be able to buy levels in Medical and Social trunk, at least not without a good justification, but we could create a list with branch skills.
Those 4 skills, as Branch 1 levels would cost [12]

Total points [61].
Total points are roughly the same if we don't penalize skill tests, and we still have 9 points on skills. Secondary and background skills are 1 level higher and this character has a broader range of abilities inside his protected niche.


Analyzes 2 (Basic Penalty -5).

But if we use the default -5 skill test penalty, the cost will skyrocket to stay at the same skill level. Not that points matter if everybody starts at the same level, but make conversions and adaptations much harder.

Conclusion
I would use the system without penalties to keep point costs in the same bracket as the modified source material.