01 / DECKBUILDING
One extra spell color
Tolabow's correction uses the whole color identity. Compare two cards, then try the checker.
See the card examples →MYSTERY BOOSTER · COMMANDER EDITION
Mystery Booster Commander
game changes
The October bulletin covers planned Rulebreaker and meld changes, plus Tolabow’s earlier Oracle correction.
A familiar card. A different deck.
Explore the illustrated guide ↓Try the Tolabow checker →
Reviewed October 20, 2026 · Official October 19 bulletin ↗
Announcement ≠ effective rules
At our October 20 review, the official rules page linked the September 25 version. Use the effective document for rulings. Source notes
START WITH THE CARDS
See what changes at your table.
02 / MELD & DOUBLE-FACED CARDS
A category change matters
The announced meld split affects an effect that looks for double-faced cards, such as Overgrown Pest.
See the before-and-after diagram →
03 / YOUR GAME FORMAT
Draft and Commander differ
A Draft deck uses its event's rules. New cards also have separate Commander and Eternal eligibility dates.
Check your format and date →Card images show the printed versions. For Tolabow, use the August Oracle correction when checking its ability.
WATCH THE DESIGN IDEA
Why break the deckbuilding rules?
Good Morning Magic explains the idea behind Rulebreaker. Watch for the design intent, then check the exact exception your commander grants.
This is design commentary. The dated bulletin and current Oracle text remain the sources for rules questions.
Watch on YouTube ↗Why we broke the rules #magicthegathering · Player loads when you press play. Open on YouTube if playback is unavailable.
BEFORE YOU BUILD
Keep the announcement and legality dates separate.
- Rules bulletin
Planned CR changes announced.
- Commander eligibility
New-to-Magic MBC cards.
- Eternal eligibility
New-to-Magic MBC cards.
The legality dates do not include acorn or playtest cards. See the format distinctions.
OCTOBER BULLETIN
Find the change that affects your deck
8 changes
903.5e
Deckbuilding
Rulebreaker timing
The announced rule supports pregame Rulebreaker abilities when the card is your commander.
Announced CR change
Oracle
Card text
Tolabow correction
Uses full color identity for the one extra spell color.
Oracle correction announced August 3; repeated in October
712 / 713
Gameplay
Meld leaves the double-faced category
The bulletin announces that meld cards will leave the double-faced category, affecting cards such as Overgrown Pest.
Announced CR change
122.1g
Clarification
Battles at zero defense
Aligns the defense-counter rule with the existing non-Siege state-based action.
Announced CR change
201.4f
Clarification
Naming an Adventure
Explicitly includes an Adventure's spell name among name choices.
Announced CR change
205.3j / 207.2c
Reference
New rules vocabulary
Adds seven planeswalker subtypes and lists rulebreaker as an ability word.
Announced CR change
608.2g
Clarification
Casting several spells during resolution
Clarifies that the player chooses their casting order.
Announced CR change
614.13a
Reference
Zone-change replacement rules
Consolidates the former 614.13b and extends coverage beyond entering the battlefield.
Announced CR change
No matching changes. This searches the eight topics, not every card. Try a rule number or reset the filters.
BUILDING WITH AN EXCEPTION?
Bring the right checks to your next game.
Read your commander's exception, check the format, then go through your deck.
Open the deck checklist →