On this page I will be posting rules clarifications and simplifications. These are not errata so much as they are the more cumbersome rules explained. This information comes from WotC and should be considered cannon. I will try and update this page as I receive more information.

1. Familiars and Summoned animals go on a spell caster's turn.
2. Tiny creatures (such as hawks) must enter into an opponents square to attack. Entering into an opponents square provokes an AoO.
3. Tiny creature can flank an opponent even though they have to enter the same square as the opponent.
4. · Casting spells with the [Evil] or [Death] descriptors is considered an evil act.
5. AoO are done with melee attacks, which precludes directing a spell effect. For example, a Spiritual Weapon cannot make an AoO.
6. Druids can also use the awaken spell to give their companions intelligence, which means the animal can advance in a character class. Familiars, however, cannot advance as a character class even though they have intelligence, since their progression is set already as a function of the spellcaster's level.
7. PHB Weapon Illustrations to Scale? WotC's Sean Reynolds talks about the grid behind the illustrations in the equipment chapter.
   "The artist added the grid for relative size comparison between the weapons. When the sketches were routing, we did get various comments back to the effect of making certain weapons bigger or smaller, but nothing about actually specking out the grid size. The grid was not given a specific scale, and was just used as a reference to keep the things in scale with each other. Given knowledge of the actual length of certain weapons (the halberd is supposed to be 5 feet long, for example), you can retrofit a scale onto it, but it's not likely that scale will be a nice neat number."
8. There has been some discussion on why Sorcerers can or can't learn arcane versions of divine spells from Bards who can cast them (or scribe them to a scroll). As in the case of Cure Light Wounds. Sean K. Reynolds tried to clear this up.
   "The intent of the sorcerer's ability to learn new arcane spells was to allow sorcerers to learn new sor/wiz spells we released in later books. The intent was never to allow him to learn bard spells. It's imprecise wording in the PHB that has led to this conclusion."
   "We tried to draw a line between divine spellcasters that can get healing, and arcane ones that can't. We gave it to the bard because the bard needed something to bring their power up to par with the other classes. It was a goof that that loophole didn't get caught. Now," if you wanted to allow a sorcerer (and only a sorcerer) to get those cure spells, it won't break anything, as sorcerers are sorta cheap-lame spellcasters anyway."
9. About Feats and Skills this question was asked: "When you are able to select a feat, do you have to select it at that time, or can you save it to be used later. The reason I ask is that you may gain a pre-requisite for a feat on an even level. I was wonder if you could save the feat to get it on that even level, or if you had to wait to get to the next highest odd level when you gained your next feat?"
   Sean K. Reynolds answered:
   I spoke to Jonathan about this, and the intent was that you'd choose a feat as soon as a feat slot became available. However, that's not explicit in the rules. So, we worked out 3 options. Each is slightly more abusive than the previous, but none are really broken enough to pitch a fit about. Whatever your DM likes.
   1. You must choose a feat when you gain the slot.
   2. You can choose your feat at any time during that level in which you gain a slot (so you could suddenly develop Iron Will when you realised you were fighting a mind flayer at level 6). (You could do this with skills, too.)
   3. You can hold your feats as long as you want and spend them at any point after you get them.
10. Can you take Free Actions during AoO.
    Answer: No, the AoO is only a melee attack, not an action.
11. About the Improved Trip feat. Lets say Joe tries to trip an Orc, but fails. The Orc uses his reaction to trip Joe. The Orc has Improved Trip. Does the Orc now get an attack on Joe?
    Answer: Yes.
12. AoO and tripping: Joe moves out of a threatened square, drawing an AoO. His opponent uses the opportunity to trip him. Which square does Joe fall prone in, his starting square, or his 2nd square?
    Answer: Since the Orc can only reach him in the first square, that is where he falls. Remember that AoOs and readied actions can interrupt someone. In other words, they go off before the action is completed.
    
13. It's WotC RPG style to not hyphenate words that don't have a double consonant where you'd want to put the hyphen.
14. When the "Bluff Skill" is used to Feint its affects last until the end of the next round.
15. It would stand to reason that you could sneak attack with a ray that does damage. It would also stand to reason that the sneak attack damage would be of the same type as the ray, so a Rog5/Sor1 could use a ray of frost to sneak attack for 1d3+3d6 cold damage.
16. A person that is a sorcerer can have a familiar. A person that is a wizard can have a familiar. If it's the same person, you only get one. One clarification going into the reprint: your sor & wiz levels stack for determining what your familiar can do.
17. Touch spells and Unarmed strikes: A character may cast a touch spell and then hold it until their next action. At that time they may choose to make a normal unarmed strike against their target. The target gets his full AC as appropriate for a unarmed attack (instead of the AC for a touch attack). If the attacker hits his target, the spell goes off first and then the damage from the punch is calculated. In other words, this should be treated just like any other unarmed strike (including AoO) with a little extra punch.
18. If you fail at a disarm, your target gets free chance to try and disarm you. This is in addition to any other attacks the character may have.
19. An AoO is an attack. You may make any sort of attack you wish as long as it is a standard action. So you could choose to trip, disarm, or even use subdual damage as an AoO.
20. Bat familiars get the ability of Blindsight. This allows them to see everything in 120'.
21. If you are fighting with two weapons and your "off-hand" weapon is one that may be hurled (like a dagger, throwing axe, or club), you may choose to use it as a ranged weapon. You take all the normal penalties for fighting with two weapons but apply your adjustments for ranged weapons to this attack. For instance, a Ranger fighting with a Long sword and a dagger could drop his opponent with his long sword and then throw his dagger at another opponent 20' away.
22. Spell casters whose ability score is not high enough to cast a spell still gains the spell slots. These spell slots may be used to prepare either spells of lower levels of spells that have had metamagic feats used upon them. Thus a Bard with a 12 Charisma and was 9th level could use his 3rd level spell slots for spells of 0-2nd level or could use them on spells that are now considered 3rd level because of metamagic feats.
23. The weapon feats that say "choose a weapon" apply to all uses of the weapon ... one-handed, two-handed, thrown, whatever. So you wouldn't need to take Weapon Focus (and so on) more than once.
24. For those that are confused about cleric turning. The rules state that a good cleric can destroy undead if his level is twice that of the Undead. This applies to his actual Cleric level, not the character level (unless he is single classed).
25. Some are curious why Search and Spot are two separate checks. here is some reasoning behind it.
    Search is Intelligence based and is a methodical concentrated effort based upon what you know to look for.
    Spot is Wisdom based and is more intuitive. It is more of a chance to just notice something.
26. The Haste spell gives the target an extra partial action. This action may be used to cast an additional spell. It is actually possible to cast three spells a round under the haste spell (and still move). This is done by casting a normal 1 action spell as a standard action, then taking your move equivalent action to move. Then you may use your haste given partial action to cast another 1-action spell. At any point in there you could have cast a spell modified by the Quicken Spell feat as a Free action.
27. Question: Are masterwork arrows 7 gp per one or 7gp per 20 or 7gp per 10?
    Answer: The table says "arrow, bolt, or bullet" - all singular terms, so it is the price listed for one of the item.
28. Question: Are monks proficient in the use of gauntlets (spiked or otherwise).
    Answer: Everyone is automatically proficient with their own natural weapons (punches, kicks, and so on for humans). The gauntlet in the PHB lets you "deal normal damage with unarmed strikes...." The spiked gauntlet does not refer to unarmed strikes.
    Therefore, I'd say that everyone can attack with gauntlets at no non-proficiency penalty. Using a spiked gauntlet requires a proficiency.
    Side note: Note that gauntlets as part of magic armor do not provide an attack bonus, just an AC bonus (when with the entire armor). This is explained in the DMG.
29. Question: Can combatants already engaged in combat be considered "Flat-Footed" against new enemies they are unaware of? Also, should the DM have them roll a Spot check to notice them?
    Answer: Yes they are "Flat-footed" unless they make their spot check. But only against those attackers they are unaware of. This means a hidden thief can use his sneak attack until his targets become aware of him. This is explained in more depth in the DMG.