I tried to design a rules expansion for OSR-style games, where you have mechanics that rely on the average 3-18 ability scores, and I started to realize how broken the modern 3-18 system has become. The OSR expansion had specific effects applied from failed ability score rolls, and while it tested well in the standard 3d6 generation games, it started to rapidly break down on games that used point-buy, epic scores, and 4d6 and drop lowest.
If a "16+" is required to play a class, using roll-under for ability score checks is difficult.
This is why we have saving throws. If a save versus paralysis was making an STR roll, that spell would hardly ever affect fighters. Castles & Crusades does a very clean sidestep around this issue by setting target numbers and primary and secondary scores, and it is the game that tackled this issue and solved the problem. Swords & Wizardry made a genius move by de-emphasizing stat bonuses, so while ability scores matter for RP, they don't matter for most mechanics.
Using saving throw charts is a way to sidestep how much of a mess the ability score system has become since the numbers are controlled and progress naturally, and the upper and lower ranges are controlled.
Many other OSR games have this issue; they make ability score modifiers highly desirable, offer ways to inflate stats to make players happy (4d6 drop lowest and assign to the desired ability score), and set up a stealth stat-inflation of required ability scores to play a class.
Why play a class with a primary attribute below 16? Reroll it. You are holding the group back. I dislike the min-max or entitled ability score feeling of many modern games.
You can play straight 3d6 rolls, but I still feel the generous ability score mods create a situation where most ability score rolls produce more unhappiness than happiness because most of your scores will suck. The few characters that roll well will be rewarded, and most will wish for better stats. It takes a lot of self-control and old-school chutzpah to play a straight 3d6 character because so many games are so generous and incentivize stat inflation by over-rewarding high scores.
But why do I feel they suck? The game designers were too generous with ability score modifiers. Plus, many modern games sadly balance games for scores 14 and over. Instead of a bonus, the high ability score becomes a required.
I am beginning to feel anything other than straight 3d6 down the line is broken. With 3d6 down the line, high scores really mean something. The scores are in the middle range, so it means more to roll against them.
But most games reward ability scores too much when they should reflect natural talents handled outside the rules where no guidance is given.
