With six primary ability scores, Intelligence is still the most overlooked option in Dungeons and Dragons. While it's the top choice for studied wizards and spellcasters, it's almost a dead investment for everyone else. Even skills related to Intelligence are best served through proficiency, experience, or temporary bonuses over raw stats. But it doesn't have to be that way, because Previous rule sets made intelligence important to everyone.
While all ability scores should be an option when creating a character, Wizards of the Coast still wants to avoid multiple skill dependency (MAD), where players feel obligated to try hard. Monks and Paladins already have this problem, needing to accumulate three or more ability values to attack and defend. Then again, unorthodox builds, like unexpected ranged holy warriors, can easily forgo their hit points and saving throws.
Intelligence is mainly for wizards and artificers
Only certain classes rely on intelligence
For all classes in D&DIntelligence grants bonuses to some skills: Arcana, History, Investigation, Nature and Religion. If you're not building someone who focuses on this, you can purposely get the lowest Intelligence value possible, 8, giving a -2 modifier to all checks. As you level up, proficiency bonuses can even cover this loss.
This leaves Intelligence to those who use it specifically as spellcasting stats: Wizards, Arcane Trickster Rogues, Eldritch Knight Fighters, and the newly tested D&D Artificers. In all cases, Intelligence helps determine spells known, the spell's attack bonus, and the saving throw's difficulty class. But, if you are only targeting allies with buffs you can still keep intelligence to a minimum. A caster that only uses Haste and Blur could be just a tiny bit smarter than the D&D the brutal or barbaric fighter of the group.
Concentration checks should use mental stats instead of constitution
Don't think, just bear the pain
One of the sustained designs from previous editions of the Dungeons and Dragons is that maintaining spells is purely a Constitution test. The difficulty class for concentration is 10 or half the damage taken, whichever is greater. This means that classes proficient in Constitution – like Fighters – are better defensive spellcasters than Mages, even if the overall divide is greater.
Pathfinder made a significant change decades ago: the spellcasting stat governs concentration, not Constitution. This meant that all mages got better at maintaining their spells as they focused on the very ability value that made them deadly. In the case of Intelligence, this would still initially only help wizards and artificers. But, another clause could be added to include all mental stats - like using maximum Intelligence, Wisdom, or Charisma.
How D&D 2024 Rules Could Make Intelligence More Important
Talents and skills that previously depended on intelligence
2024 D&D The rules made some adjustments to Intelligence, albeit small. During social interactions, characters can be influenced even if they are hesitant. In these rare cases, the difficulty class is 15 or the Intelligence score, whichever is higher. However, a hostile enemy cannot be reasoned with without magic.
Intelligence used to be extremely important in the third edition of D&Dallowing access to more skills, talents and even known languages. This meant that skilled monkey classes like Rogue and Bard would accumulate Intelligence to have an absurd number of skills. On the other hand, the skill-deprived Cleric would also have a decent amount of Intelligence to compensate for his natural deficiencies. The question remains to what extent Intelligence should impact total competencies, as it cannot be a complete one-to-one ratio. One option is to grant a skill bonus per modifier, without losing a base skill per negative Intelligence.
The intelligence was also used for a whole chain of combat talents: Whirlwind Attack, a spectacular move coveted by fighters that allowed them to deliver one attack to every enemy within five feet - possibly eight hits in total. Such a character needed 13 Intelligence and Dexterity, Specialization (which improved armor class), Dodge, Mobility and Spring Attack. Several of these talents need to be reworked, as the movement towards D&D 5e is much more relaxed.
It's not clear why Wizards of the Coast moved away from the heavy focus on Intelligence in Dungeons and Dragons. This was possibly due to vocal complaints from long-time players. It could also have been an internal choice based on the developer's playstyle. But in either case, there's not much reason to have more than 8 Intelligence if you're not a Mage or Artificer who will be attacking directly.