Alternate Forms and Alternative Abilities

A while ago, I asked a question on the forum that was not satisfactorily answered, and when I googled the same question, I found nobody had answered it, and there were no good answers for it in books that really should have answered it.

Last night, I figured out the answer (it'll look really obvious when I explain it, I'm surprised nobody worked it out.  Perhaps they did and felt no need to tell anyone because it's so obvious?), and it is this:

The cost of an alternate ability in an alternative abilities framework is (15+modifiers) + ((Template Cost - Master Alternative Ability)*0.9)

What the hell are you on about?

Alright, so GURPS has two power frameworks, both by PK, that heavily lean on Alternative Abilities: Divine Favor and Sorcery, the latter of which is clearly pitched at those who want to replace the standard magic system with an ability-based magic system.  This means these systems should able to handle shapeshifting and the best way to handle shapeshifting is with Alternate Form (or Morph).  But given that Alternate Form is, itself, a form of Alternative Ability, how do you make it cost the right amount?

Let me break it down more carefully for you

What is an Alternative Ability?

Let's say you have a Psychokinetic ability that you can either use as a shield (DR 4 (Forcefield +20%) [24]) or as a crushing blast (innate attack (crushing, 5d)) [25]).  That is, if you are shielding yourself, you cannot attack, and if you attack, you cannot shield yourself.  In this case, you may take the cheaper of the two abilities (the DR, in this case) at 1/5 the cost. The total advantage would be 30 points (25 + 5).  You could add further alternative abilities, provided their cost wasn't higher than the most expensive ability unless you're willing to rejigger costs.  So, we could add ST 5 telekinesis [25] for +5 more points as an alternative ability to the crushing innate attack, and so on.

What is an Alternate Form

Alternate Form grants you the ability to change your shape and thus your racial template.  The cost is (15+modifiers) + (how much your template cost exceeds your native racial template * 0.9).  So, if you can turn into a wolf, which is worth less than a human, if costs you 15 points (plus modifiers).  If you can turn a T-Rex, which is worth way more than a human, then it costs 15 points + 90% of the cost of being a T-Rex (so if it cost 100 points to play a T-rex, you pay 90).

Alternate Form as Alternative Ability

Here's where we run into a problem: If you wanted to add the ability to turn into a wolf to your pyschokinesis (right? Just go with it, it's an example), then when you've turned into a wolf, you can't use your psychokinesis.  But... wolves aren't psychokinetic anyway, so, uh, what's up?  The general agreement is that Alternate Form can't benefit from Alternative Abilities.  It's already an Alternative Ability.

Question asked and answered. What's the problem?

Alternate Forms can get really expensive.

Let's talk about the pope.

The Pope! Well, a pope.

Let's say the pope has, I don't know: Religious Rank 8 [40], Is Devoutly Catholic [-1], Nice Hat [1] for [40] points (plus, like, all sorts of popey stuff).

Let's say the Pope also has Divine Favor 16 (he's a really cool pope) for [200].  When he talks to God, God really listens.  For example, the Pope could purchase Part the Seas as a Learned Prayer.  This would cost him 32 points, but it buys him 160 points worth of ability.  WOW!  That's quite a nice deal.

But let's say that the Pope instead wanted to call upon God's power and become Pope-Hulk!  Pope Hulk has all the same traits he had before, plus ST +20 [200], Berserker [-10], Odious Personal Habit (Pontificating) -2 [-10], DR 4 [20] for a total of [200] points.  So if we but it as an alternate form, it costs us 15(-10% divine) + 180 (90% of 200), or 194.

You wouldn't like me when I'm pontificating

195 is less than 200, so should be legitimate Alternative Ability, but we've just established that you can't take Alternate Forms as an Alternative Ability (it's already an Alternative Ability), so he has to pay the full 195.  That is, he pays 32 points to part the sea, but 195 points to turn into Pope Hulk.

However, the reason that it's already an alternative ability is that it lets you replace your previous abilities.  Currently, Pope Hulk is built thus:

• Pope [40]
• Divine Favor 16 [200]
• Pope Hulk [200]

The three templates layer each other. With this build, Pope Hulk can still use his Divine Favor.  That is, he can also part the seas or throw a plague of locusts on San Francisco for being wicked, or whatever else it is that he wants while also being super-strong.  Thus, we're not actually treating it like an alternative ability, which is why it's so expensive.  The proper answer should actually be:

Pope Form:

• Pope [40]
• Divine Favor 16 [200]

OR Pope Hulk

• Pope [40]
• Pope Hulk [200]

Since both templates are 240 points, Pope Hulk form is no more expensive than the standard template and is thus 15 (-10% Divine Favor).  The pope only needs to pay ~14 points to HULK OUT.  If the pope wants to use Divine Favor again, of course, he needs to relinquish his Pope Hulk form and go back to standard Pope form which is no different from any other divine power, where he can only use one at a time.

This also applies to Sorcery: As long as the form you want to change into is no more expensive than your own native template + cost of Sorcery, your value is 15.  Always subtract the cost of your Alternative Ability framework from your alternate form if your alternate form doesn't have access to your Alternative Abilities.

I made you a diagram!

Some people still have trouble grasping it, especially in the context of Divine Favor and Sorcery and other alternative ability frameworks.  So here's a diagram!

The first thing to understand is that a power set is not defined by an alternative ability framework.  What makes a power Divine is that it has the Divine modifier, and that's it.  Nothing stops someone from having Damage Resistance 5 (Divine -10%) [23] all the time, and not as a learned prayer.  Sorcery actually explicitly includes this when discussing "new spell slots." You're effectively buying a second copy of the alternative power framework for the sole purpose of having two alternative abilities running at once.

Alternate form is like that.  It's just a power with the "Divine" modifier slapped onto it.  The cost of the new form is everything from your old character, minus divine favor (or Sorcery, or whatever alternative ability framework you associate this ability with) + 15 points.  This is standard Alternate Form.  Any alternate form can do this.  You could make a form that was exactly like your normal form, except with claws and without the ability to speak, or with bonus ST and less IQ, or whatever.  That's just how Alternate Form work: It lets you add/subtract traits, as a big package deal, from your character.

Divine Favor (or Sorcery) is the alternative ability framework.  It has a big, chunky cost, and you buy all of the abilities associated with it as alternative abilities.  These get a 1/5 cost discount, and you can only use one at a time.  Alternate Form is not an Alternate Ability and has no association with Divine Favor.  It's an unrelated trait.

Except that we choose to give it up when we switch forms.  Thus, there's a logical association between the two ("I can be in this form, or I can use my prayers"), but there's not a mechanical association between the two (It is not purchased as an alternative ability of Divine Favor).

I hope that clarifies it a bit.