Well I've always meant to do this, but it's been taking a while. Anyway, essentially the players should exercise their brainsin things other than just building decks and playing cards: design your own cards! Remember, people may be rating the cards and criticizing the cards from their own opinions, and quite frankly I'll be checking for overly brokenness (no matter how much you argue, this is the most common mistake among rookie card desginers, it's a habit to break out of).
All cards need a layout, and we usually follow the same layout to remain consistent. Here are the layouts for the cards:
(Name of Card)
(Card Type: ie. trap, spell, continuous trap, etc.)
The above layout works for all types of YGO cards, but you apply level/type/attribute and ATK/DEF for monsters only.
Example Effect monster:
During your standby phase, you may gain 1000 life if Undine is on the field.
For Duel Masters:
(Name of Card) (cost #) (Colour/element of card)
(Card Type: i.e. creature, spell, etc.) (Sub type for creatures: i.e. Elf, etc.)
(Power: i.e. 4000)
Giant Worm 8 Darkness/Black
Creature - parasite worm
Whenever Giant Worm attacks, the defending player discards 2 cards.
"Nobody ever sees this and walk out sane." - Jack
(Name of Card) (Cost: we use WGUBRfor the colour symbols for white, green, blue, black, red)
(Card type: i.e. Sorcery, creature) (Card sub-type: i.e. elf, arcane, etc.)
*note, from the casting cost, we automatically know the card's colour.
Lobelia, Angel of Paradise 3WWW
Legendary Creature - Angel
Flying, Protection from all colours
"Perfection of Paradise."