Good question!!!!

I personally feel the attack penalties make up for the increased armor class, along with the equipment differences. However, I am not as good a rules lawyer when it comes to size, so I'll let others field this one.

er, attack penalties? Small-sized characters get +1 to attack and +1 to AC. (I think of this as the "broad side of a barn" rule. It wouldn't be very easy for a Great Wyrm Gold Dragon to hit the broad side of a barn with an arrow, any more than it would be easy for a human to hit a toaster with an arrow.)

More explanation?

I would think it would be ok to scale the different creatures. Take a look at the gnome. +2 Con, -2 Str. That could be seen on a medium creature. The same goes with the rest of the traits. Or compare Halfling and Gnome. It isn't like they both get a +2 Dex, which sort of stacks with the size modifier to AC. Similar arguments could be made with the medium races made small. Just be sure to take all size factors into consideration: reduce speed for Small, reduce height/weight (with weight scaling 8:1), etc. I personally would change the gnome's dodge bonus vs. giants, but even that is arguable.

I'm sure there are limitations and odd cases where a strict scaling could lead to imbalance, but in general I think it is ok. For example, a half-orc's +2 Str sort of double-buffs the character with the +1 AC and +1 hit/damage. It also reduces the grapple penalty Again, it could be argued that it isn't a big deal. Then again, on average they would be using smaller weapons.

I say go for it. =)

Size penalties are based on a comparison to a Medium sized character.

Medium has no penalties. A Gnome that was freakishly large for a gnome and is now considered medium would not gain the size bonus that a gnome gets.

Generally speaking the attribute penalties and bonuses each race gets has already taken into consideration of the character balance.

A gnome without the size bonus, would be balanced since the movement penalty offsets the AC bonus. You gain a benefit and gain a drawback. Same as a small elf, who would gain an AC bonus, but lose a movement ability.

There are lists on how to create races to be balanced, but I can't think of where right now. Basically follow the list, and create the race from scratch using the existing race as a template. See if it balances.

And the relatively minor consideration of carrying capacity.

Do the bonuses and penalties for being size Small balance each other out?

Game-balance wise? Without allowing for monster-style sudden jumps in ability scores? Yes. Being small gives a slight weapon damage reduction, balanced by a universal +1 on attack rolls and AC. The converse is true with simply being large -- more weapon damage, but a flat -1.

Now, there are all kinds of reasons to not allow simple size adjustments, but those are essentially flavor and niche protection.

I was going to allow it on a case-by-case basis; I was going to redesign entire races as small or whatnot. Thanks for the info though :)

Switching from Small to Medium and visa versa is pretty easy to balance (minor carrying capacity adjustments, movement 30 for Mediums and 20 for Smalls, +1 to hit and AC if Small) so long as you don't mess with the ability score adjustments (which is only slightly difficult to justify being that Gnomes' and Halflings' -2 to strength is cited as being due to their small size).

Once you start allowing Large creatures, though, you open up the playing field to all sorts of opportunities for broken characters, though.

ditto. same goes for fine or tiny. those are potential game breakers.

I'm not sure if that's the case, if you take into account the size adjustments.

For example, I'm building a chipmunk character (long story, and as of right now, it's mostly a test to see how an awakened animal could be built up as a PC), and we sized them at diminutive (particularly small breed running at about four inches in length).

The bonuses to AC and hit (+4/+4) are offset by the additional -2 Strength (bringing the Chipmunk to -10 Strength when compared to a rat -- the animal whose statistics are used for a squirrel according to the newest dragon). I gain a +2 bonus to Dexterity, bringing it to a total of +6. The natural abilities for the chipmunk are not that great. ;)

The chipmunk has 12 Monk levels, which makes the damage something like 1d6 + 5 (Greater Magic Fang) - 4 (Strength of 2), which is not that insane for this level of play.

In my opinion, it really depends on what the base stats of the creature are. If it was a tiny size creature with a 10 base strength and you allowed it to drop to diminutive, then you may have a problem with powergaming.

The fact that I have no carrying capacity is also something of note.

i suppose there are no absolutes and everything depends on situation. however i did have a player who wanted to run a fine pc and man did it ever mess things up.

I don't doubt it.

Like I said, I think it's a case-by-case scenario.

I'm finishing up my "chipmonk" at the moment, and I'll post the full product when all is said and done for review here.

Of course about the large stuff. Reach and big weapons just throws everything out of whack. I figure PCs are either small or medium-size, and I will stick with that.

Thanks.