Updated Rules

Any Hero/Character specials & Locations
Any team using a home base may also use Any Hero/Character Specials. You may still not use Any Heroes with Battlesites.

Basically, all teams are allowed to use a Homebase. The choice of using Any Hero/Character Specials OR a Battlesite deck remains with the player unless otherwise noted (e.g. Sanctum Sanctorum Homebase).

Definitive KO
If a Character takes enough hits so that they would count towards both Spectrum and Cumulative KO, that Character is KO'd, regardless of Inherent abilities/Specials/anything else.

Aritifact duration
Non-OPD Artifacts are considered to last for the remainder of the current battle unless the card states otherwise. Similarly, OPDs are for the remainder of the game.

Specials coded LN
Specials coded LN can no longer be played defensively. You must play it on your turn as an offensive action.

Example: Marauder's Vertigo

Specials coded DZ
Specials coded DZ can no longer be played defensively. You must play it on your turn as an offensive action.

Example: Nightcrawler's Trick Transport

Attacks that are shifted
Attacks that are shifted cannot be shifted to a character where there would not be an effect.

Example: "Target character must discard 1 card" cannot be shifted to a character who has no placed cards.

Four Freedoms Plaza
With the Four Freedoms Plaza, attacks which are shifted This means that it is legal to defend with Power cards, Basic Universe cards, Training cards, DoubleShot cards, etc. but it is not legal to defend with Specials, Activators, etc. which do not have a "To Use" requirement.
 * must be blocked and
 * must be blocked by utilizing the character's power grids.

General rule
Cards which affect the opponent or the opponent's characters cannot be played defensively. Some cards which have been noticed as being played incorrectly: Mr. Fantastic's Object Bounce (Opponent's team may not use Universe cards to attack or defend against Mr. Fantastic) and The Leader's Twisted Mentality (All attacks by opponent's team must be made against Leader until Leader is KO'd or cannot be attacked). Read the text of the cards carefully - if it changes your opponent, it cannot be played defensively.

Any cards which are in play prior to an attack cannot be negated.
For example, if Professor X plays Telepathic Coordination and on a later turn makes a level 6 attack, Telepathic Coordination cannot be negated as part of the defensive action. On the other hand, if Professor X plays Telepathic Coordination with a level 6 attack, then a negate or a level 8 Power card can be used to block the attack and either one would stop the entire attack from succeeding and prevent Telepathic Coordination from remaining in play. By playing the 2 together, you risk losing the ongoing effect of the Special.

Unusables
During the discard phase, any card which is not usable must be discarded. You cannot depend on a random draw to make that card usable in order to keep it. However, if you have a card (placed or in hand) which can make the card usable, then it should not be discarded. For example, if a character has been KO'd and Morph is on the front line, and the player draws a Special for that KO'd character, it must be discarded as unusable, even if Substitute Death is in the deck. However, if Substitute Death is Placed or in Hand, then the KO'd character's Special can be kept since Sub Death would make it usable. If 2 characters were KO'd and both of their Specials came up in the same hand, then the player would need to decide which of those specials can be kept and which must be discarded since Sub Death could not make them both usable. Similarly, if all 4 characters had a Universe card placed to them and a Teamwork is drawn in a hand with no power cards, then the card must be discarded as unusable.

Specials which Target a character
Specials which Target a character can only be played against a character. They cannot be played against non-characters like Specials or Battlesites. If a special acts as an attack and has a secondary condition that targets a character, the attack may be made against a non-character, but the secondary effect does not occur.

Grunge's Inherent Ability
Grunge's Inherent Ability requires that he be hit with some attack that can act as more than one type of attack. It does not require that a MultiPower Power card land on his record. For example, if Onslaught hit him with Mutant Gestalt (which acts as 2 types of attacks), then the condition of Grunge's IA would be fulfilled.

Specials coded HQ
Specials coded HQ are considered One Per Deck

Example: Mr. Fantastic's Inventive Genius

Specials coded FA
Specials coded FA can no longer be played defensively. You must play it on your turn as an offensive action.

Example: Thing's Aunt Petunia

Specials coded GD
Specials coded GD should always be considered to have the word "OR" instead of the word "AND" in the phrase "If successful, acts as a level 1 Energy AND Strength attack."

Example: Onslaught's Mutant Gestalt

If the Any Character Special "Fortress of Solitude" or "New Universe" is played in a battle
If the Any Character Special "Fortress of Solitude" or "New Universe" is played in a battle then the player using it may not have ventured more than 2 mission cards that battle.

Specials coded BQ
Specials coded BQ may not be used to retrieve Any Hero/Character Specials from the Dead Pile.

Example: Any Hero/Character's Web-Headed Wizard/Wizard in Top Hats & Tails

All level 7 Any-Power Power cards
All level 7 Any-Power Power cards are considered One Per Deck

All versions of Ally cards which state that a teammate MAY make a follow up attack
All versions of Ally cards which state that a teammate MAY make a follow up attack should read MUST.

The Battlesite Deck
The Battlesite Deck may only have one of each coded Special under it. The code of a Special is found in the lower left hand corner of the Special.

Battlesites
Battlesites can only defend attacks made against them with power cards or activator cards (which pull defensive Specials). Special cards for the Front Line Characters (even negates) cannot be used to defend for a Battlesite.

Marvel Universe, Marvel Manhattan, Omniverse and Team OverPower
Marvel Universe, Marvel Manhattan, Omniverse and Team OverPower cannot be used as Battlesite.