I just read under Goblins that they get a +1 size bonus on attack rolls, then went and looked it up. Can anyone explain why they get that? I knew about a damage bonus for being huge (hitting harder), and the AC bonus for being small (harder to hit), but where does the attack roll bonus come from? I find it hard to imagine a 3 feet creature being able to properly attack a normal sized being at all, let alone better than a medium sized humanoid. Is there a logic here that I'm missing or is this just for balance purposes?
... and the AC bonus for being small (harder to hit), but where does the attack roll bonus come from
The AC bonus basically balances out the attack bonus. So small creatures attacking each other have a neutral relative AC.
I find it hard to imagine a 3 feet creature being able to properly attack a normal sized being at all, let alone better than a medium sized humanoid.
This is a great line, but there are some things to remember here:
- The attack bonus only applies to "making contact". Weapons are doing less damage based on size. A normal human attacked by fairy is the proverbial "broad side of a barn". However the fairy is basically throwing pins and toothpicks with a relatively low mass, so it's not doing a lot of damage.
- In the fantasy world, the 3ft gnome can have 16 STR which means that she can clean & jerk 230lbs (104kg) or deadlift 460lbs (208kg). That's a scary 3 footer.
- At higher levels this happens all of the time, with Medium fighters tackling Huge Dragons (+2 sizes). Of course, to pull this off, they need a bevy of magical gear. (like flaming toothpicks of doom)
- Also note that "bigger" creatures tend to have larger dice for their HD. So a fey creature get d6, while a magical beast get d10 and a dragon gets a d12. The correlation to size is not perfect, but in general bigger creatures get more HP.
The basic idea is that a smaller thing sees the majority of things as bigger targets. As size bonuses are constants rather than proportionate (i.e. creatures of Small size all get the same bonuses from being Small size) to speed play, and most of the universe's targets are Medium, Small creatures gain that +1 bonus to attack rolls. The bonus to attack rolls continues to increase as the creature becomes smaller and becomes a penalty as the creature becomes larger.
It leads to some weird results though.