How does the ki pool class feature work when there are two sources, one of which has restrictions?

Question

One of my players wants to play a monk with the scarred monk archetype which specifically states that he may only use his ki pool to power a ki strike and the archetype-specific powers. He then wants to multiclass into ninja, which gains a second source of ki without said restriction.

In my personal interpretation of the rules, either the restriction stands and the ninja ki pool merely adds to the restricted pool or only the ki granted from the ninja ki pool may be used unrestricted. The latter sounds like too much bookkeeping, while the former seems too harsh. Is there any official ruling on this? If not, how would you handle this situation?

Answer 1

The restriction is only applied to one class's features

The Scarred Monk says:

A scarred monk cannot spend ki points to make an additional attack at her highest attack bonus when making a flurry of blows, to increase her base speed, or to give herself a +4 dodge bonus to AC, nor can she use any of the other powers normally granted to monks that utilize their ki pools.

While monks normally are able to use their ki for these effects:

• Enhance his melee damage with certain effects (magic, cold iron, silver, etc), also known as ki strikes;
• Make one additional attack at his highest attack bonus when making a flurry of blows attack, or; (Not allowed)
• Increase his speed by 20 feet for 1 round, or;(Not allowed)
• Give himself a +4 dodge bonus to AC for 1 round.(Not allowed)

This means that the monk can only use their ki powers to make ki strikes and to use the archetype's Mortifications.

But when you become a Ninja (obligatory reference), you also gain a ki pool that can be used to fuel certain ninja abilities:

• A ninja can make one additional attack at her highest attack bonus;
• She can spend 1 point to increase her speed by 20 feet for 1 round;
• Give herself a +4 insight bonus on Stealth checks for 1 round.

While some are similar to a monk's usage of ki points, they are ultimately not the same abilities, those are ninja abilities and unrelated to a monk's usage of ki points. So the restriction that applies on the monk archetype will not affect ninja abilities and her usage of ki points.

Additionally, we also know that a ninja's ki pool will stack with ki points granted by any other class, into a single combined pool:

If the ninja possesses levels in another class that grants points to a ki pool, ninja levels stack with the levels of that class to determine the total number of ki points in the combined pool, but only one ability score modifier is added to the total.

But not only that, the ninja also says this:

The ninja can now use ki points from this pool to power the abilities of every class she possesses that grants a ki pool.

Which means that the ki point points granted by your ninja class levels can be used by any other class that also has a ki pool, including monks (archetyped or not), and these points have absolutely no restriction. Those points are fueling the Scarred Monk's ki pool, and thus can be used for mortifcation or ki strikes, while also fueling the ninja's ki pool and can be used to fuel ninja abilities.

Answer 2

So Pathfinder and 3.5e have this thing where they say {class} can’t this thing when they mean {class} doesn’t give you the ability to do this thing. The clearest example of this was for 3.5e’s wizard specializations, which stated the wizard could not cast spells from banned schools—but we know that was untrue for a multiclass wizard, who could cast those spells with his other class. There are other examples of this, and I think that the scarred monk makes the most sense when viewed through this lens.

Here is the scarred monk text:

These ki points can only be spent to activate powers granted from mortifications or to make ki strikes. A scarred monk cannot spend ki points to make an additional attack at her highest attack bonus when making a flurry of blows, to increase her base speed, or to give herself a +4 dodge bonus to AC, nor can she use any of the other powers normally granted to monks that utilize their ki pools.

The text here takes the time to explicitly list out all the things monks can “normally” do with ki points. To me, this reads as the scarred monk archetype explicitly stating that the scarred monk doesn’t get these abilities that a monk ordinarily would.

That, to me, does not mean that a scarred monk is incapable of getting other features that use ki points, for example by multiclassing with ninja. Scarred monk says its ki points are only for some of the monk’s usual features, and not for the other features monks normally get. It doesn’t say anything about ninja features.

And ninja says that it can do these ninja things.

Pathfinder is an exception-based ruleset. That means that we expect rules to say one thing, and then another rule to say something else, overriding it. Melee weapons use Strength... until Weapon Finesse comes along and says they use Dexterity some of the time. Scarred monk says you can only use its ki points for specific things... until ninja comes along and says you can also use it for these other things.

So my recommendation is to not think of scarred monk as a banlist so much as just “this class isn’t giving you that feature.” If you get it elsewhere, then go ahead.