Design philosophy:

• No counters or tokens of any kind (counterspells are fine).
• Less powerful cube cards than average.
• Simple cards are preferable to complicated ones. (Disfigure vs Gollum's Bite)
• "Good" removal starts at 3 mana; anything less should have caveats. (Murder vs Diabolic Edict)
• Sized to accommodate up to 4 players.
• Mana fixing should be fast for 2 color decks and slow for 3 or more colors.
• Baltimore Singleton (Singleton except for the fixing lands.)
• No planeswalkers. Text on cards should not refer to planeswalkers, if able. (Lava Spike vs Lava Spike)
• Universes Beyond cards are acceptable in small numbers so long as they aren't drastically off-aesthetic. (Assassin Gauntlet vs Captain America, First Avenger)