Does an Antimagic Field suppress the ability score increases granted by the Manual or Tome magic items?

Question

There are several "manual"/"tome" magic items that permanently increase a character's ability score and the maximum value for that score by 2: the Manual of Bodily Health, the Manual of Quickness of Action, the Manual of Gainful Exercise, the Tome of Clear Thought, and the Tome of Leadership and Influence.

Would the ability score increases granted by one of those very rare manuals/tomes be suppressed while in an antimagic field?

I'd like to imagine their effect augmenting a character with magic, but not being a lasting magic effect that can be turned off. Is there anything in a book that gives a specific answer to this, or effects like this?

Answer 1

The ability score increases are part of the character, not maintained by magic

The description for the Tome of Clear Thought is as follows:

This book contains memory and logic exercises, and its words are charged with magic. If you spend 48 hours over a period of 6 days or fewer studying the book's contents and practicing its guidelines, your Intelligence score increases by 2, as does your maximum for that score. The manual then loses its magic, but regains it in a century.

The last sentence is important: the only magic mentioned in the description is the magic-charged words. The manual loses this magic after being used to increase your ability score. So while the rapid increase in your intelligence over the course of a week is magical, no magic is involved in maintaining that increased intelligence, because there isn't even any remaining magic that could be maintaining it. Contrast this with a Headband of Intellect, which says:

Your Intelligence score is 19 while you wear this headband.

This item unambiguously stops working as soon as you remove it from your head (or as soon as you enter an antimagic field).

Another useful precedent is the spell Feeblemind, which sets a creature's Intelligence and Charisma scores to 1 indefinitely but has a duration of Instantaneous. In this case, magic is used to "shatter [the target's] intellect and personality", but once their intellect is shattered, no magic is required to keep it shattered. Of course, this is a spell whose duration is explicitly stated, but it makes the point that magic can cause an ability score to change permanently in a way that is not contingent on an ongoing magical effect.

Answer 2

A practical ruling: the increases are not suppressed, because keeping track of it is difficult.

I will admit up front: I am not sure about the "rules as written" answer to this question. I am certain that there is no concrete guidance, and synthesizing the existing rules and official guidance on antimagic field is tough, and may just come down to "it's unclear, ask your DM".¹

However, I've run a few high level campaigns where antimagic field was used frequently, and based on that experience, my ruling here is: don't worry about having to readjust your scores in an antimagic field. Running the game with antimagic fields is already a tough task for the DM. The overhead with keeping track of all the magical abilities that are in play already slows combat down considerably. There is a reason we have numerous questions about how AMF works, and when it comes into play, there are already lots of rulings that need to be made by the DM in the heat of combat. Adding dynamic ability scores into the mix is just another thing to keep track of, and requires the players to recalculate their bonuses to hit, saving throw bonuses, and spell save DCs on the fly based on their position on the board, and for the DM to be aware of those recalculations at any given moment. In other words, the juice isn't worth the squeeze.

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^{1 Several answers were posted after mine tackling the rules head on. For a rules as written ruling, I would personally give my endorsement to Ryan C. Thompson's explanation.}

Answer 3

An antimagic field would not suppress the ability score, as the increased ability score is not magical that way

The Sage Advice Compendium has this to say on how to figure out if an effect is magical:

Is the breath weapon of a dragon magical? If you cast antimagic field, don armor of invulnerability, or use another feature of the game that protects against magical or nonmagical effects, you might ask yourself, “Will this protect me against a dragon’s breath?” The breath weapon of a typical dragon isn’t considered magical, so antimagic field won’t help you but armor of invulnerability will. You might be thinking, “Dragons seem pretty magical to me.” And yes, they are extraordinary! Their description even says they’re magical. But our game makes a distinction between two types of magic:

• the background magic that is part of the D&D multiverse’s physics and the physiology of many D&D creatures
• the concentrated magical energy that is contained in a magic item or channeled to create a spell or other focused magical effect. (...)

Determining whether a game feature is magical is straightforward. Ask yourself these questions about the feature:

• Is it a magic item?
• Is it a spell? Or does it let you create the effects of a spell that’s mentioned in its description?
• Is it a spell attack?
• Is it fueled by the use of spell slots?
• Does its description say it’s magical? If your answer to any of those questions is yes, the feature is magical.

Lets look at the example text of Tome of Clear Thought (which itself clearly is magical, as it is a magic item):

This book contains memory and logic exercises, and its words are charged with magic. If you spend 48 hours over a period of 6 days or fewer studying the book's contents and practicing its guidelines, your Intelligence score increases by 2, as does your maximum for that score. The manual then loses its magic, but regains it in a century.

The only reason to think the ability increase was magical is that it is caused by a magic item. But once you get the ability score increase, it is entirely independent of the book. The description does not state that you do need the book for it thereafter in any way, and it would need to say so if you did. There are no secret rules. Compare this for example with gauntlets of ogre power which say: "Your Strength score is 19 while you wear these gauntlets." There the altered ability score is dependent on the magic item. Not here. You could lose or destroy the book, and it would do nothing to your ability score.

So, is the ability increase magical? Let's go through the list:

• Is it a magic item? No.
• Is it a spell? No.
• Is it a sspell attack? No.
• Is it fueled by spell slots? No.
• Does its description say its magical? No. The description does not say the increased ability score is magical.

As we answer all of those with no, the overall answer is no. The effect may have been caused by magic, but the increased score now is the kind of background magic that that is part of the D&D multiverse’s physics and the physiology and is not suppressed by an antimagic field.

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PS: What I do not have an answer for is if the manual still would detect as magical after you use it? It says explicitly that it loses its magic, but it can regain it in a century, so there still must be some latent magic. It also does not cease to be a magic item, so going by the fist bullet of the criteria, it still is magical. I am not sure if this part can be resolved just from the written text.

Answer 4

To answer your question with as much detail as possible, let's look at the Tome Of Leadership and Influence's description.

Tome Of Leadership and Influence

This book contains guidelines for influencing and charming others, and its words are charged with magic. If you spend 48 hours over a period of 6 days or fewer studying the book's contents and practicing its guidelines, your Charisma score increases by 2, as does your maximum for that score. The manual then loses its magic, but regains it in a century.

The DMG does also have it in the Magic Items tables, and it describes the tome itself as magic, but the effect of the ASI isn't directly said to be magical in and of itself. The magic of the tome seems to be more akin to having guidelines in the book that will improve the reader's current abilities, and not attuning to it to improve a stat(like a Ring of Protection for AC). I would say that the tome itself, if it still has its magic, cannot be studied while in an Anti-Magic Field, but the effects of it are not suppressed, as they are not magical by themselves. Somewhat magically obtained, yes. Magical, no.

Answer 5

The text for the Manuals doesn't directly address this, but we can reasonably conclude the effect shouldn't be suppressed by connecting antimagic rules and the entire description of the Manual (in this case, Quickness of Action).

This book contains coordination and balance exercises, and its words are charged with magic. If you spend 48 hours over a period of 6 days or fewer studying the book's contents and practicing its guidelines, your Dexterity score increases by 2, as does your maximum for that score. The manual then loses its magic, but regains it in a century.

I've emphasized three key points in this paragraph- the first point is that the book's words are what is charged with magic.

The second point is that the magical effect of these words is to increase your Dexterity score and Dexterity maximum. This magical effect is the crux of your question- magical effects are normally suppressed inside an AM field by definition.

However, the third point is our resolution. After you gain the benefit of this magical effect of reading these words, the manual loses its magic, but you do not lose the ability increase, even if you lose the book. This means the magical effect is instantaneous and without duration.

If you hit someone with a fireball and then cover them with an antimagic field, they don't get the HP back, because the magic causing the effect has already passed.

The conclusion of this is that if you're reading the book in an antimagic field, you can't progress through or finish the 48 hours of reading, but once you've read the book, like any other instantaneous effect that modifies your stats, it sticks.

Finally, as a narrative point based on this text, you study the book and practice its guidelines. I believe a reasonable implication here is this manual's magic gives it the words that guide the person attuned to it how to best improve its current ability in themselves, kind of like a personal trainer/tutor in a book. Once you've completed this magically accelerated exercise/study, you are stronger, faster, smarter, etc, and while magic caused it, it's no longer magic.