Size effect on AC, Attack rolls

[marune]

Where is detailled the effect of size on AC, attack rolls and skills?

 

[FEADIN]

In the PHB, Combat chapter.
ATTACK BONUS
Your attack bonus with a melee weapon is:
Base attack bonus + Strength modifier + size modifier
With a ranged weapon, your attack bonus is:
Base attack bonus + Dexterity modifier + size modifier + range penalty

Table: Size Modifiers
Size Size Modifier Size Size Modifier
Colossal –8 Small +1
Gargantuan –4 Tiny +2
Huge –2 Diminutive +4
Large –1 Fine +8
Medium +0
Same way for ac bonus/penalty, hide skill is +4 each size under medium or -4 each size bigger than medium.

 

[Ferret]

In the Monster manual glossary under Size.

 

[TheGogmagog]

SRD Improving monsters

SIZE INCREASES
A creature may become larger when its Hit Dice are increased (the new size is noted parenthetically in the monster’s Advancement entry).
A size increase affects any special ability the creature has that is affected by size. Increased size also affects a creature’s ability scores, AC, attack bonuses, and damage values as indicated on the tables below.

Table: Changes to Statistics by Size
Old Size*	New Size	Str	Dex	Con	Natural Armor	AC/Attack
Fine	Diminutive	Same	–2	Same	Same	–4
Diminutive	Tiny	+2	–2	Same	Same	–2
Tiny	Small		+4	–2	Same	Same	–1
Small	Medium		+4	–2	+2	Same	–1
Medium	Large		+8	–2	+4	+2	–1
Large	Huge		+8	–2	+4	+3	–1
Huge	Gargantuan	+8	Same	+4	+4	–2
Gargantuan	Colossal	+8	Same	+4	+5	–4
*Repeat the adjustment if the creature moves up more than one size.

Table: Increased Damage By Size
Old Damage (Each)*	New Damage
1d2		1d3
1d3		1d4
1d4		1d6
1d6		1d8
1d8		2d6
1d10		2d8
2d6		3d6
2d8		3d8
* Repeat the adjustment if the creature moves up more than one size category.