• Aaron K

Investigation: The Unnecessary Skill

Hey Reader!

I'm starting a deeper look at some of the skill checks and abilities in D&D, and today we're looking at one of the skills that, in truth, I've never really understood what it does, which is ironic since it's one of the top five skills people should probably take proficiency in if they have the opportunity.

This skill is Intelligence (Investigation), and since it's a commonly used skill in most groups, I thought I'd take a few minutes to note what the skill says about itself, what the issue is with this presentation, and a quick fix that solves the issue.

I. What Is "Investigation"?

On Page 178 of the Player's Handbook, we read the following:

"When you look around for clues and make deductions based on clues, you make an Intelligence (Investigation) check. You might deduce the location of a hidden object, discern from the appearance of a wound what kind of weapon dealt it, or determine the weakest point in a tunnel that could cause it to collapse. Poring through ancient scrolls in search of a hidden fragment of knowledge might also call for an Intelligence (Investigation) check."

Now this is very interesting, as all of the other Intelligence skills start with a variant of, "This check measures your ability to recall (fill in the blank)," and in its own definition Investigation overlaps with a number of these skills. Nature checks allow you to recall information about terrain, which presumably would include tunnels and where the weak points may be in a tunnel, as one example.

But it gets more interesting: things like the location of a hidden object could just as easily be discerned through a Wisdom (Perception) check, but if you are a high Intelligence character, you can "deduce" that location with Investigation, effectively removing the need to perform a Perception check at all (at least rules as written).

So this led me to think, "Wait a minute: so what is this skill, actually, if it can replace other Intelligence checks and even some Wisdom checks?" And that's what led me to the following discovery...

II. The Issues with Investigation

The issue with Investigation is that it's a catch-all for many things, and thus becomes a default skill to replace other skills. If you don't want to roll for Nature, see if you can "deduce" the truth from things you've read. If you don't feel like rolling Perception, see if you can "deduce" what might be stalking you based on clues. If you didn't take proficiency in Arcana, see if you can "discover" the truth in a tome by using Investigation and "piecing together the information."

So in reality, the skill is a Prediction skill with a bunch of added fluff, allowing it to suffer from "skill creep" due to the gray areas of that fluff. And that's dangerous for a game, as it means that those with access to this skill in effect gain proficiency with other skills because of the skill creep.

So how do we fix this issue? I present a simple solution.

III. The Solution: Replace with New Skills

The solution is that we need more skills that are more narrowly tailored. The skill should be replaced by two skills: a Mechanical or similar skill for identifying traps, mechanisms, and other non-Arcana, non-History, non-Religion, and non-Nature stuff as that doesn't really have a replacement.

Second, we should create a Deduction or Prediction skill, allowing people to use this skill to assess the probability of something, or perform the "Sherlock Holmes"-style investigation. This could still overlap with other things, but it grounds it firmly in its own realm: the realm of speculation, not reality. So a player can speculate on what is following them, but until they roll Perception they won't know for sure.

After these have been applied, we should use other skills more heavily. Why the Wisdom (Medicine) roll should only be for stabilizing someone and treating diseases instead of also identifying the disease/cause of injury is beyond me (as Survival is already used in this way). Use a Nature check to identify things involving stonework, morasses, etc. The skills in question are in no danger of becoming the new go-to skill, and it will make them more relevant to a game governed by a small handful of skills, which we will be discussing in the coming months.


When D&D first came out, there were no skill checks. And some have even argued that it should return to this, just relying off of the base stats instead of adding your proficiency to a select number of skills. I think skills are a nice addition to the game, but I also think that some skills are inherently more powerful than others, and when that happens I want it to be for a good reason.

In a world full of sudden perils and unexpected danger, Perception and Acrobatics will always be more useful than, say, Medicine. But if a skill exists, it should have its own defined realm so that when that moment comes up it can have its moment in the sun. And Investigation gets in the way of other skills getting to shine.

We may do more of these in the future, but on the whole I like the D&D skills, so don't expect a series. But if you see a skill and wonder about if it is staying within its realm, could be better handled by another skill, or anything else, let us know in the comments below! We plan to look into Arcana and Medicine in the future, but more on that in a few weeks.

Until then,

Aaron K