Topic: Player intelligence vs. character intelligence
Let me preface by saying that I have little experience, having only played and DMed less than five times, but I theorize often.
How that I would have my players role-play intelligence is that I would let the game role-play it for them and let them roleplay it as much as they want. Similar to physical performance, there are mental performance checks in-game and they are there precisely to determine character smartness and how well it does for them. I would allow a character with 8 INT to do brilliant things because their player is brilliant, because eight is two points below average. Brilliant plans are not exclusive to the above average in intelligence; they are just consistent and correlative to those with above average of our conception of intelligence. Our conception of
intelligence is vague: "Numerous definitions of and hypotheses about intelligence have been proposed since before the twentieth century, with no consensus reached by scholars." I'd let the player adjudicate themself if they decide that what they would otherwise do is not possible by their conception of their character; The player can not do whatever they do want not to do.
If I believed that a plan was too smart for their character to formulate, I'd work with them to have that be their plan anyway by having an NPC suggest the plan. This garners the best of both worlds, roleplaying appropriately low intelligence, but benefiting from one's own knowledge. If I believed that a plan was too dumb for their character to formulate, I'd give them subtle hints as to a better plan and/or I'd retcon so that they have a better plan. For example,
Player: "I lockpick."
DM: "You notice that the padlock is made of iron. Surely, easier to be broken than picked with your mace which is made of stronger stuff." Granted, such wording is condescendant. A check (e.g., Spot) can be pretended to be rolled, to mislead that their PC figured it based on their own wits.
I've often heard people recount in pain their group's Barbarian who had sub-10 INT , but roleplayed dumber because they believed otherwise. By the numbers, two to three is what marks the threshold to minimal human sentience. Three = full lingual capability. Parrots and great apes are on the brink of human baby talk intelligence. The pack-hunt tactic of flanking can be considered smart, but the animals formulating the tactic have sub INT 3. Yet, Steve the Half-Orc Barbarian with INT 8 will still act stupid enough to abandon flanking tactics.
3 INT, minimum WIS, and formulating ingenious master-plans? I'm going to draw the line at 3 INT: once past and above 2 INT, you can formulate any plan. What of INT 3 humans? They could formulate the plans, but perhaps they can't convey them well. There are people with cerebral palsy that only have impaired motor functions, but they can claim to not be mentally handicapped. If that's the case, despite being able to formulate master-plans, they could still be considered mentally handicapped. There's more than one part to the brain for the intelligence score to affect. To keep things simple, there's the 3 INT milestone and the rest is up to the player. Anyone can recall a time when they decide to abandon flanking tactics despite having average intelligence.
Keep in mind, an 18 ability score is considered tremendous. Characters regularly possess ridiculous ability scores and that's hard to roleplay. Generalizing the issue:
"How do I do stuff that I can't actually do?"
"The game establishes mechanics for actions. For example, although you may not be able to wield a greatsword in real life, you can play a Half-Orc Barbarian with 18 STR and the game calculates you swinging a greatsword to attack something by having you roll a d20, adding attack modifiers, then rolling for damage, adding damage modifiers.
Another example: Although you may not be able to bluff to your mom in real life, you can play a Gray Elf Rogue with 18 INT and the game calculates you telling a lie to deceive someone by having you roll a d20, adding skill modifiers, then having the victim roll for Sense Motive, adding their own skill modifiers.
In this way, you can do what you normally can't, both in a physical sense and a mental sense."
Tackling the issue anew:
A player can metagame to have their character know everything about their opponents? No. I meant that I'd be laissez faire with roleplaying intelligence which is different than knowledge.
Player intelligence vs. character intelligence is believed to require adjudication because of the feeling of cheating when thinking smarter than one believes that the character thinks. One must establish whether or not it is cheating and wherefore the feeling originates. The feeling originates from preconceived notions of intelligence levels. Intelligence levels ability score numbers are examined:
Is setting fire to an enemy camp a tactic that an INT 3 Half-Orc Barbarian could come up with?
Just what separates INT 0, INT 1 (being higher than 0), INT 2 (being lower than 3), and INT 3 (at which "a creature of humanlike intelligence has a score of at least")?
Can an animal come up with the idea of setting fire to an enemy camp? No.
Can an animal learn to set fire to an enemy camp? Yes.
Can an animal learn that setting fire to an enemy camp is good? No.
Can a creature of humanlike intelligence come up with the idea of setting fire to an enemy camp? Yes. There is no plan a creature of humanlike intelligence cannot conceive. Plan sophistication vs. hammer-time can be taken up as an issue in turn-based combat and the metagame itself as a different topic. Idiot savants are a perfect example of paradoxes to that issue, emphasizing that intelligence is multifaceted yet woefully determined by a single ability score.
