When Dungeons & Dragons characters search, what check should players make? Based on my experience playing with a hundred or so fifth-edition dungeon masters, most answer Wisdom (Perception). Nonetheless, many DMs ask for Intelligence (Investigation) checks instead.
So what character should search a door for traps? Based on the Dungeon Master’s Guide, pick the wise cleric. Based on the skill descriptions, pick the clever wizard. Based on tradition, pick the thief and—if you play fifth edition—run for cover because they can’t spot anything. Besides initiative checks, search checks rate as the second most common in the game, so you would think everyone would agree. We don’t.
All this uncertainty means that as a DM making a call for your table, you decide. I’m here to help.
To complement Perception, D&D’s fifth-edition playtest included a Search skill. So during exploration, PCs “make a Wisdom (Perception) check to detect hidden creatures and an Intelligence (Search) check to detect hidden objects (such as traps and secret doors)”. This makes the difference between Perception and Search seem like noticing creatures versus spotting objects—surely not the intended distinction, and perhaps one source of confusion that led the designers to drop Search in favor of Investigation. At least everyone could agree to use Search for searching.
The game rules for Investigation explain, “When you look around for clues and make deductions based on those clues, you make an Intelligence (Investigation) check.” The bit about looking around for clues makes Investigation seem like a more useful superset of Search. Aside from treasure, clues rank as the most common thing for a search to uncover. Even traps only prove fun when players find clues to their presence. Falling down a pit: no fun. Investigating a puddle and finding an edge where the liquid meets a seam in the floor: fun.
For searches, opt for Intelligence (Investigation) checks. Investigators notice clues and uncover things outside of plain sight. Investigators know where to look, so they check under a drawer to find the envelope tucked in the joint. Most characters ignore the scuffs on a stone floor, but an investigator notices them because the marks show where the statue slides to reveal a trap door. Someone skilled at Investigation spots the ordinary but significant details that the keen-sensed barbarian overlooks because such details seem insignificant. Sometimes players know where to look too, so if a player asks to peer under drawers, they spot that letter.
In contrast, perception enables characters to notice things that simply require keen senses, for example the sounds of an invisible creature, the master rogue Waldo in a crowd, or the cat obscured by shadows. “Your Wisdom (Perception) check lets you spot, hear, or otherwise detect the presence of something. It measures your general awareness of your surroundings and the keenness of your senses.” Perception can reveal the obscure, but it can’t expose something hidden from all the senses.
Many D&D fans, including me, tend to think of Investigation and searching as active in contrast to passive Perception. While this pattern frequently holds, don’t rely on it to distinguish the skills.
Such thinking leads players to make two checks to look around, one for percieving and one for investigating. Better to avoid such repetition. See How to Avoid Boring Rerolls of D&D’s Ability Checks. Players who make one check to find nothing in an empty room feel disappointed. Why invite a second, time-wasting check?
Freelance designer Teos “Alphasteam” Abadia explains how a distinction between active and inactive skills leads players to game the system. “Spycraft did that, with one skill for actively looking and another for possible noticing. It led to absurd behavior. You would enter an enemy camp, but state you were not looking around. That way, your better Notice skill would kick in.”
Sometimes the difference between Investigation and Perception blurs. Typically, when characters pause to examine and interact as they look, call for an Investigation check. This tends to reinforce the distinction of an investigator noticing the details in the mundane, plus it balances the value of the overvalued Wisdom (Perception) check with the undervalued Intelligence ability and Investigation skill.
D&D is a team game and when different character architypes skills and abilities contribute to a group’s success. By using the Intelligence ability and the Investigation skill, players who excel at those less pervasive knacks gain a chance to shine.
This approach amplifies the importance of not completely blocking a group’s progress with an Intelligence (Investigation) check. Fifth edition minimizes the value of the Intelligence ability so much that unless a party includes a Wizard, then no character may have a score higher than 10. In an essential investigation, give any required information, and then reward the sleuths with additional insights.
As for all those 8 and 10 Intelligence characters played by smart D&D players, they show the changing fashions of tabletop roleplaying. In the hobby’s early days of random ability scores, players who valued character immersion often felt obligated to play a low intelligence character as a knucklehead, complete with dangerously foolish decisions. Now, I rarely see such a commitment.