It's about trade-offs. You can roll your stats to try to get a 16-18, but you take the chance of getting a 3-7 in another stat. You also take the chance they you might end up with a net +3 or +4 modifier bonus rather than the +6 from the array.
Well, no, and arguably it shouldn't, because at the end of the day, this is a character the player would hopefully be happy playing.This will only work if we assume that the DMs will make players keep the first character they roll. In my experience that just doesn't happen.
I look forward to someone asking wizards what happens with their attribute boosts they get from leveling when the character's attributes are already maxed out at 20.
This will only work if we assume that the DMs will make players keep the first character they roll. In my experience that just doesn't happen. The other problem is the internet has taught me that people will cheat when they roll characters.
I look forward to someone asking wizards what happens with their attribute boosts they get from leveling when the character's attributes are already maxed out at 20.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.