Special thanks to Discord user Manic L0rd for catching the issue of monsters with 0 ATK battling. For most of the early years of Yugioh, when two monsters with 0 ATK battled each other, they would be destroyed by the battle. However, this interaction was overturned in 2011 such that neither monster would be destroyed. Research points to the change finally being implemented in Rulebook Version 7.2 released with Structure Deck Dragunity Legion [REF].

Thus, in Edison Format, when two Attack Position monsters with 0 ATK battle each other, they will be destroyed as a result of battle. Keep this in mind when using "Battle Fader" or "Dandylion" in your Deck!

Special thanks to discord user MMF for compiling information pertaining to how card interactions that create infinite loops (the infamous "Pole Position") were ruled during Edison Format, as well as additional information  concerning the End-of-Turn discard a player must perform to ensure they do not exceed their hand size limit. The Edison Format Rules page has been updated with these rules (numbered #10 and #11). Hop on over to give them a read, or click "Read More" to see them presented below. Additionally, "Pole Position" has been added to the Individual Rulings page.

Thanks to Discord user STLF for stumbling upon this detail! Research reveals that Union Monsters printed prior to Structure Deck: Seto Kaiba [REF] had a Condition restricting the number of Union Monsters that could be equipped to a Monster, and also the circumstances under which they could be destroyed in place of the equipped monster. Additionally, they could only be Special Summoned from the Spell / Trap Card Zone into Attack Position. This Condition would cease to be printed, and would be retroactively removed from Union Monsters through via errata. When playing Edison Format, remember that ALL Union Monsters have the following Condition:

• "(A monster can only be equipped with 1 Union Monster at a time. If the equipped monster would be destroyed [as a result of battle], destroy this card instead.)"
  

Be sure to familiarize yourself with the specific Conditions that existed for your favourite Union Monsters at the time of SJC Edison before you start playing, just in case the current card text differs!

Duel Terminal 1 released on January 29, 2010, reprinting many old cards while also introducing new strategies. But not all the new cards within the set were deemed tournament legal for the purposes of SJC - Edison or other SJC events at the time. Given the limited nature of Duel Terminal machines, Konami's official policy was as follows:

"New DUEL TERMINAL cards are not tournament legal until they are available through some other method, such as inclusion in a Hidden Arsenal set or some other form of Booster Pack or Deck" [REF].

For a complete list of cards first introduced in DT01 that are NOT LEGAL for Edison Format, click HERE.

Internet archeological forum activity points to a discrepancy in rulings surrounding one of the most powerful cards in the format - "Future Fusion". Special thanks to MMF for bringing this to the community's attention and providing a timeline of events regarding these changes!

the TL;DR (click "Read More" for the revised rulings):
- You CANNOT activate "Future Fusion" while "Vanity's Fiend" prevents Special Summoning.
- You CANNOT activate "Future Fusion" while a "Barrier Statue" monster is face-up UNLESS the Fusion Monster you intend to reveal has the allowed Attribute.
- You cannot reveal "Five-Headed Dragon" while "Koa'ki Meiru Drago" is face-up because it is DARK.

The Rulings & Erratas page has been updated to include an entry elucidating the effect of "Destiny Hero - Diamond Dude". Dodge costs, ignore Activation requirements, and snub pesky Conditions! Be warned, "Gold Sarcophagus" has some problematic text!

Unsure what your opponent means by "it doesn't activate, it misses the timing"? Confused why your opponent is saying "during damage calculation" before activating Kalut? Unsure why Catastor doesn't destroy face-down monsters but a FLIP monster's effect still activates after being shuffled back into the Deck by Ehren? We've been hard at work compiling a thorough "Rulings & Erratas" page complete with the most updated card texts that were available at the time of SJC - Edison 2010. Find hidden tech to up your game and innovate new strategies! Afterwards, head on over to the Battle Phase Breakdown for a  detailed  breakdown of the  7 timings of the Damage Step, and use this handy flowchart to make sure your effects are resolving on time!