"It's a trap!" Finding traps in D&D 5E

My first time as a player, in the not so new D&D 5th Edition, I played my favorite class (of course): a Rogue. Back then, I hadn't read thoroughly the PHB so I made the wrong assumption, by reading the skills list, that my Rogue will be needing Intelligence (Investigation) to look for traps. Imagine my surprise when I tried to look for them and my DM tells me to roll Perception! We argued a little, but at the end I conceded (because you don't want to piss-off your DM =P), and ask him to let me change my character, so that I may have proficiency in Perception instead of Investigation. He agreed.

And that was it. I was going to just accept that now you look for traps with Perception. Even when it felt weird, because (for me), when you're looking for traps... well, you are actively looking for them, right? For me that's "investigating", and it kind of fits the Intelligence stat because you're supposed to know what you are looking for. I mean, when I think about it, if me (the actual real me) was supposed to be in a dark dungeon looking for traps, I will die on the first step because I have absolutely no clue what a trap should look like. It's a know how, knowledge, ergo Intelligence. I consider Perception (and Wisdom) a more intuitive thing, instincts and senses are involved. But anyways, as I said, I was accepting the new system as is. Until running The Rise of Tiamat adventure!

Perception and/or Investigation?

So here I was reading my beautiful new module, when I found out —in the Tomb of Diderius section— that a player can make a Wisdom (Perception) check DC 24 or an Intelligence (Investigation) check DC 18 to find a plate that is part of a trap, but not the trigger. The trigger itself was somewhere else and it required a successful Wisdom (Perception) check DC 22 (I'm not including any details about the actual trap to avoid any spoilers). Now, hold on a second! Why can a character find part of the trap with either Wisdom (Perception) or Intelligence (Investigation)? And why is way easier to do so with the latter? Alright —I said to myself— the actual trap still requires Wisdom (Perception) check to find, let's stick to that. So I kept reading, and three pages later I found another trap, that can be detected with a successful Intelligence (Investigation) check DC 15! What!?

After that, I checked the skills again, more thoroughly. I had actually read them before, the very day after the discussion with my DM, and even when I saw that the Investigation skill mentions you can find hidden objects, I concurred with my DM because the book specifically says you look for traps and secret doors with Perception. So as I was saying, I checked again more carefully. Here I quote the Investigation skill (italics are mine):

Investigation. When you look around for clues and make deductions based on those 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.

And here is the Perception skill (again, the italics are mine):

Perception. 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.
For example, you might try to hear a conversation through a closed door, eavesdrop under an open window, or hear monsters moving stealthily in the forest. Or you might try to spot things that are obscured or easy to miss, whether they are orcs lying in ambush on a road, thugs hiding in the shadows of an alley, or candlelight under a closed secret door.

And next to the Perception skill is a side-box about finding hidden things (and yes, you guessed, italics are mine):

Finding a Hidden Object
When your character searches for a hidden object such as a secret door or a trap, the DM typically asks you to make a Wisdom (Perception) check. Such a check can be used to find hidden details or other information and clues that you might otherwise overlook. In most cases, you need to describe where you are looking in order for the DM to determine your chance of success. For example, a key is hidden beneath a set o f folded clothes in the top drawer of a bureau. If you tell the DM that you pace around the room, looking at the walls and furniture for clues, you have no chance o f finding the key, regardless of your Wisdom (Perception) check result. You would have to specify that you were opening the drawers or searching the bureau in order to have any chance of success.

Now, let's wrap it up. With Investigation you can look around for clues and make deductions based on those clues, so you might deduce the location of a hidden object. And with Perception you might try to spot things that are obscured or easy to miss. But when you are trying to find a secret door or trap, you have to use Perception to find hidden details or other information and clues. Didn't the "clues" turf belonged to Investigation? OK, rules are meant to be interpreted —hell, they are meant to be broken!— and if the book has a special side-box about finding traps and secret doors with Perception, so be it, I'm cool with that. But then I buy this official module saying in one page you can find the trap with Perception and in the other you can do it with Intelligence. It depends on the type of trap now or what?

It's all about consistency

Well it's true that you may say that the kind of trap and even circumstances can decide if you use one check or the other; but the thing is, that's not fair for the players. Because players are going to invest their resources, during character creation, in the things they know their character is going to need (just as I did with my Rogue). So it's obvious they are going to ask their DM "What do I need to find traps?", and either option it's fine (Wisdom or Intelligence), as long as it is consistent. You can't tell the player "you need Wisdom", and then (as written in the Rise of Tiamat) ask him to roll Intelligence to see is she notices the trap.

For me using Intelligence makes more sense (as I said at the beginning of this post), but only if you're looking. So, what I'm thinking on doing as a house rule, is to tell my players: If you're actively looking for a trap or hidden door, you'll use an Intelligence (Investigate) check, but if you're just passing by you'll use a Wisdom (Perception) check, or even your Passive Perception score. What do you think about this house rule?