This is Part Four of a series of articles looking at creating a set of Starfinder feats under specific constraints. The point of these is to offer practical examples of how I approach developing and writing supplemental rules for tabletop RPGs. Rather than just blather on about things as I think of them, I go over issues as I encounter them in a real-world example.

The goal of this project is to create the “Missing Starfinder Legacy Feats,” a Starfinder-compatible version of every feat in the PF core rulebook that doesn’t have an SF match. (We discussed the impact of having to do that, whether that’s a good idea or not, in Part One.)

You can find previous entries here — Part One , Part Two, Part Three — or just the finished feats (as they are written) here.

We’re done Acrobatic, Acrobatic Steps, Agile Maneuvers, Alertness, Alignment Channel, and Animal Affinity. And that brings us to Arcane Armor Mastery and Arcane Armor Training.

And a brand new problem.

Both Arcane Armor Mastery and Arcane Armor Training are designed to allow characters with arcane spellcasting to overcome the penalty of arcane spell failure when wearing armor. But Starfinder doesn’t differentiate between arcane spellcasters and any other kind, and doesn’t have any arcane spell failure mechanism. These PF feats interact with two sets of rules Starfinder doesn’t have! As a result we can’t just use the trick we did for Acrobatics and Alertness, and look for design space in the SF rules to match the intent of the version of the PF feats.

So, we’re going to have to make up some entirely new benefits, guided by little more than the feat names and the kinds of PF characters who might take the feats.

Every class in Starfinder has access to proficiency with light armor (to date, anyway), and none of the spellcasting classes (again, so far) have access to heavy armor. But there’s no problem spellcasting in heavy armor — the classes just aren’t proficient with it. And it’s easy enough to get proficiency, with a feat or multiclassing, so that’s not likely a fruitful direction for developing an SF version. On the other hand, it means any feat we create tied into light armor is accessible to all spellcasters.

That givens us a where or when for bonuses for these feats, but not a what. Worse, since we know we have to do both Arcane Armor Mastery and Arcane Armor Training, we need a bonus that can scale up, or two related bonuses. And, we need them to not give the kinds of numerical bonuses that can break the game math in Starfinder — just having Arcane Armor Training give you +2 if you can cast spell and are wearing armor, and Arcane Armor Mastery give you a +4, won’t work. they’d immediately be the go-to of any spellcaster, and might even convince soldiers to take one level of technomancer just to qualify for them.

But just because Arcane Armor Training gives spellcasters access to better mundane defenses in PF doesn’t mean it has to do the same thing in Starfinder. We could, in fact, have the feats not be training in armor for arcane characters, but training in arcane armor for any classes.

Viewed through that lens, we can decide the feats give you bonuses only against spells and spell-like abilities. That’s a much narrower field than a bonus to all ACs, but still makes sense with the names, AND is still appealing to fighting-casters who might have wanted the PF version (though we are opening it up to a broader group, potentially).

While we can’t hand out universal bonuses without risking imbalance, we can create situational benefits a player can call on from time to time, especially if they have a cost. So, what we need are defensive benefits, tied to armor, against spells and spell-like abilities, with a cost. Since we are designing for Starfinder, it seems a good idea for that cost to involve Resolve Points, and t make sure it’s useful but not a no-brainer, we should limit it’s uses.

And that leads us to these.

ARCANE ARMOR MASTERY
You can focus mystic energies into your armor, creating a powerful beneficial magical talisman.
Prerequisite: Arcane Armor Training, proficiency with light armor, Mysticism 9 ranks.
Benefit: When you expend your arcane armor talisman to reroll a saving throw, you roll 2d20 and take the higher of the two results.

ARCANE ARMOR TRAINING
You can focus mystic energies into your armor, creating a beneficial magical talisman.
Prerequisite: Proficiency with light armor, Mysticism 1 rank.
Benefit: You can take one minute and expend on Resolve Point to create an arcane armor talisman in one upgrade slot of your armor. You can only have one arcane armor talisman in existence at a time, creating another one automatically causes any existing ones to fade, and your arcane armor talisman only works for you and only when you are wearing the associated armor. While your arcane armor talisman exists, you cannot recover the Resolve Point used to create it.

When you fail a saving throw against a spell or spell-like ability, as a reaction you may expend your arcane armor talisman and reroll the saving throw.

.

Tomorrow we’ll take on Arcane Strike and… Armor Proficiency (Medium)?

PATREON
Like all my blog posts, this is brought to you by the wonderful patrons of my Patreon! If you want to see more of these types of instructional how-I-do-the-work-of-a-professional-RPG-developer, or any other of my kinds of content, please join my Patreon to support their creation and let me know what you want to see!