If I have a character with INT of 18....then he is smarter than me, the player. How do I get to play a smart character if I lack the abilities?
Oh, good grief. Tell me you're just being argumentative.
You've never played 1E or 2E AD&D? You've never played any RPG that didn't use skills--where you had to use your noggin instead of just make a dice throw?
You've never played like this...
[FONT=TimesNewRoman,BoldItalic]The Pit Trap (Old Style)[/FONT]
GM: “A ten-foot wide corridor leads north into the darkness.”
John the Roguish: “We move forward, poking the floor ahead with our ten foot pole.”
GM: Is about to say that the pole pushes open a pit trap, when he remembers something. "Wait, you don’t have the ten foot pole any more. You fed it to the stone idol.” [if the party still had the pole, John would have detected the trap automatically]
John the Roguish: “I didn’t feed it to the idol, the idol ate it when I poked its head.”
GM: “That doesn’t mean you have the pole back. Do you go into the corridor?”
John the Roguish: “No. I’m suspicious. Can I see any cracks in the floor, maybe shaped in a square?”
GM: Mulls this over, because there’s a pit trap right where John is looking. But it’s dark, so “No, there are about a million cracks in the floor. You wouldn’t see a pit trap that easily, anyway.” [A different referee might absolutely decide that John sees the trap, since he’s looking in the right place for the right thing].
John the Roguish: “Okay. I take out my waterskin from my backpack. And I’m going to pour some water onto the floor. Does it trickle through the floor anywhere, or reveal some kind of pattern?”
GM: “Yeah, the water seems to be puddling a little bit around a square shape in the floor where the square is a little higher than the rest of the floor.”
John the Roguish: “Like there’s a covered pit trap?”
GM: “Could be.”
John the Roguish: “Can I disarm it?”
GM: “How?”
John the Roguish: “I don’t know, maybe make a die roll to jam the mechanism?”
GM: “You can’t see a mechanism. You step on it, there’s a hinge, you fall. What are you going to jam?”
John the Roguish: “I don’t know. Okay, let’s just walk around it.”
GM: “You walk around it, then. There’s about a two-foot clearance on each side.”
I'm sure you're capable enough to run your INT 18 thief without having to rely on a dice check.
EDIT: Actually, how could one explain doing this? :
That's a supernatural ability. It's like magic.