3e-style Psionics using 4e-style tools

[dataweaver]

In this thread, I intend to rough out a primarily skill-based take on psionics, using 3e’s Psionics as inspiration but with a more open-ended and customizable approach. Basic concepts:

1. Either the “Magical Scope Parameters” from GURPS Thaumatology or the Effect Modifiers from Ritual Path Magic will be used in determining what a “psychic skill” can do. How they’re applied is described below, though it’s still subject to change.
   
   
2. Each “psychic power” has a Potency advantage which comes in levels and is priced according to how broad or narrow the power is, just like how Power Talents work in GURPS Powers — except that Potency doesn’t normally add to any dice rolls (its use will be detailed shortly). The cost per level still needs to be determined; but I suspect that 5, 10, or 15 points per level would be too cheap. My gut instinct is 10, 20, or 30 points per level; but I haven’t done any playtesting to verify or disprove this. (EDIT: vierasmarius has convinced me that the only fair pricing would be 5, 10, or 15 points per level.)
   
   The Potency advantage also takes a “power modifier” as per GURPS Powers, allowing this system to quickly and easily be adapted for use as chi skills, divine miracles, magic spells, spiritual rituals, etc. I’m just using the “Psionic” modifier as a working example.
   
   “Potency 0” is effectively an Unusual Background; and as such, it may have a cost as low as zero points. Note that the option from Thaumatology about allowing spellcasting without Magery at a -5 penalty can be adapted to Potence: if this option is in effect (say, for worlds where “all humans are latent psychics”), anyone can learn psychic skills; but they suffer a -5 penalty if they don’t have at least Potency 0.
   
   
3. Every psychic skill defines a Primary Parameter from the aforementioned Scope Parameters. The effective rating of the Primary Parameter equals the rating of the associated Potency attribute plus the skill roll’s margin of success.
   
   
4. The skill can have any number of Secondary Parameters, as long as the parameter in question makes sense for he psychic phenomenon that the skill represents. These Secondary Parameters start at zero by default, and can be raised as high as the associated Potency trait by taking a skill penalty at a one-for-one exchange rate; each Secondary Parameter’s skill penalty can be bought off as a Technique.
   
   If you wish, you can apply some or all of your margin of success to a Secondary Parameter, or even split it up among several Secondary Parameters. Ignore the Potency cap when doing so.
   
   It’s also possible that a given skill might need a Secondary Parameter with a non-zero default rating. If this is the case, the skill has a minimum Potency prerequisite, at least equal to the highest non-zero Secondary Parameter and probably higher (though how much higher, I’m not sure yet).
   
   
5. Prerequisites are rare. In general, if being able to do X implies the ability to do Y, then Y defaults to X at some penalty rather than X having Y as a prerequisite.
   
   
6. Skill difficulty is a reflection of its “complexity”, as the term is defined in the New Invention rules: Simple skills are Easy, Average skills are Average, Complex skills are Hard, and Amazing skills are Very Hard. Yes, this requires a GM judgment call; advice on how to judge it should be provided. Conversely, this provides a basis for using the Invention rules to develop new skills.
   
   
7. psychic abilities that don’t involve skill rolls can be added as Perks. They follow the same rules as outlined above, except that there’s no “margin of success” benefit due to there not being any margin of success to benefit from.
   
   Perks might seem to be a little cheap; but bear in mind that if they can do a lot, it’s because they’re coupled to a Potency advantage. Compared to the skills, the perks are very reliable in that you don’t have to worry about failure; but you also don’t get the benefits that come from beating the target number by a substantial margin. A case could be made that they should be cheap Advantages rather than Perks; but I wouldn’t price them any higher than 5 points each — slightly more than the cost of buying a Hard skill at no penalty.
   
   
8. In general, most of the special rules that Powers provides for customizing its powers (e.g., Extra Effort rules) can be applied to this system with little to no modification. Likewise, some options available in Thaumatology (such as the Ritual Magic option) could be applied to this to further customize it — though you’d need to watch out for unintended consequences, such as the switch from Skills to Techniques clashing with the buying off of Secondary Parameter penalties as Techniques.

That’s about as far as I’ve gotten. Comments and criticisms welcome; suggestions and advice especially welcome.

[D10]

I liked it, was about to go to bed when I saw this and thought it was a gem!

In sum, ill refrain from giving further feedback as im sleepy and havent read it all, but I loved at first glance and will post more later on the week.

[vierasmarius]

I like what you've got so far. I now definitely see what you meant by a Skills + Advantages approach that's different from the existing 4e Psionics Powers.

I do have one concern about how skills and Potency interact. The effectiveness of a psychic skill is based on the Margin of Success, with Potency adding directly to that margin. In effect, Potency is a limited Talent, but you've priced it at twice what a Talent would be. This may encourage players to just pump up skill (if there aren't many per category) or IQ instead.

Personally, I'd lessen the impact of skill, so people who want raw power buy more Potency. Skill should be used for finesse - precise control, special techniques, etc. Maybe they can sacrifice skill to gain power, but it should be draining (higher FP cost?) and not overall as efficient as having higher Potency to start with.

[dataweaver]

Note that +1 to skill does not equate to +1 margin of success, unless you’ve pretty much maxed out the skill: the average margin of success at skill level 10 (assuming success) is 23/12; the average margin of success at skill level 11 (again, assuming a success) is 28/12. So buying a +1 to your skill at that level gives you slightly less than a half-point (5/12, to be exact) increase in your margin of success, assuming you succeed. As your skill gets higher and success gets more likely, this rate increases, until it approaches one; but it never quite gets there.

But you raise a good point: unless I jimmy the system so that margin of success has less of an impact than Potency does, I probably shouldn’t price Potency any higher than an equivalent Talent would cost. So 5, 10, or 15 points per level of Potency. Keeping it from getting out of hand is a function of setting up the progressions of the Parameters as something reasonable.

Note also that I haven’t said anything about what the FP costs are. That’s because there may not be any: I’m debating the possibility that FP costs come from incorporating “Costs FP” into the Power Modifier. Likewise, incorporating Requires Preparation into the Power Modifier might result in lengthy rituals a la Path Magic instead of the “concentrate for a second or two” model that one expects from Magic and 3e Psionics. And so on. That said, this is still very much in the brainstorming stage.

And then there’s the possibility of applying the Extra Effort rules to Potency to exceed its usual limits…

[vierasmarius]

Originally Posted by dataweaver

So buying a +1 to your skill at that level gives you slightly less than a half-point (5/12, to be exact) increase in your margin of success, assuming you succeed. As your skill gets higher and success gets more likely, this rate increases, until it approaches one; but it never quite gets there.

Of course, higher skill also raises your chance of success - quite significantly, at skill 10-11. If you've only got a 50% chance of success, an ability that gives +1 MoS is only adding that to half the rolls, because the other half fail outright.

And then there’s the possibility of applying the Extra Effort rules to Potency to exceed its usual limits…

Personally, I'd handle all increases to Potency in a manner like this, though with variations to the standard Extra Effort model. Perhaps have a fixed -2 skill penalty per +1 Potency instead of the usual -1 per 10% increase, and 1 FP per +1 instead of a flat 2 FP per attempt. Or have a higher skill penalty but the option to spend FP to counter the penalty.

Anyways, that's just my preference, to fit my view of fictional psions. It remains to be seen how any of this actually functions in play.

[dataweaver]

Originally Posted by vierasmarius

Of course, higher skill also raises your chance of success - quite significantly, at skill 10-11. If you've only got a 50% chance of success, an ability that gives +1 MoS is only adding that to half the rolls, because the other half fail outright.

True enough. That seems fair, though: a fractional increase in your margin of success if you succeed plus an improved chance of success on the one hand, or a full point improvement if you succeed but without the improved chance of success on the other hand. Yeah; I’m comfortable with them both having the same cost.

Originally Posted by vierasmarius

Personally, I'd handle all increases to Potency in a manner like this, though with variations to the standard Extra Effort model. Perhaps have a fixed -2 skill penalty per +1 Potency instead of the usual -1 per 10% increase, and 1 FP per +1 instead of a flat 2 FP per attempt. Or have a higher skill penalty but the option to spend FP to counter the penalty.

Anyways, that's just my preference, to fit my view of fictional psions. It remains to be seen how any of this actually functions in play.

I’ll be reviewing the Extra Effort rules shortly.

[vierasmarius]

Originally Posted by dataweaver

True enough. That seems fair, though: a fractional increase in your margin of success if you succeed plus an improved chance of success on the one hand, or a full point improvement if you succeed but without the improved chance of success on the other hand. Yeah; I’m comfortable with them both having the same cost.

I think your math is off. If you have two characters, one with skill 11, one with skill 10 and a +1 to MoS, they will have the same MoS for the same dice rolls, with only one exception: The skill 11 character will succeed on a roll of 11, with MoS 0, while the skill 10+1 character will fail on a roll of 11. On a roll of 10 they'll both have MoS 1. Also, if Margin of Failure matters the skill 11 character is even better off, since when he fails it will be by one point less.

[smurf]

I prefer 4e over 3e and had fun converting a character to it. Really thinking of what was 3e's bargain basement to a focused 4e of what is it going to be.

[dataweaver]

I don’t want this thread to turn into an advocacy war; so I’ll just say that I liked 3e’s approach of an Advantage that defines how much you can do and a set of skills that define what sorts of things you can do with it — and it’s that approach that I’m seeking to emulate here.

If you prefer 4e’s approach over 3e’s approach and don’t see any way for 4e to have room for both, have fun with Powers as written; this thread probably isn’t for you, as I’m attempting to do something that isn’t GURPS Powers.

[D10]

Why not simply transcribing the 3e system to 4e and fixing it where it breaks down ?

I liked Power levels costing different ammounts for different powers (esp cheaper than pk or telepathy for instance), I also liked how some power thresholds allowed access to cool habilities (like combat sense).