Forbidden cards are essentially "banned" cards, while limited simply means that you can only put 1 in a deck, semi-limited is up to two in your deck only. Some cards in the OCG/TCG are either forbidden, or limited, and this is due to their ability to create an unbalanced experience for the game.
Unlike in the TCG/OCG where you can have multiple limited cards with different names in your deck, in Duel Links you can only have a total of 1 limited card in your deck. For example you have limited card A and limited card B, and you already put 1 card A in your deck, you cannot add card B to your deck even if they are not cards of the same name. This rule is also true for semi-limited cards in which you can only have a total of 2 semi-limited cards in your deck.
You're new to yugioh aren't you? Whenever a deck becomes an meta defining (meaning near everyone is running the same deck because it's the strongest in the game). A banlist hit occurs, weakening that deck so that players will play something else. This is done because.it helps new decks and cards compete without raising the game ceiling too much and keeps the pvp scene from getting stale.
This is not permanent however. As cards will come off the list over time as the card pool continues to grow.
Anonymous 3hour ago
I was very happy with the Nerf then I decided to hit the PvP to see some new decks with new ideas and OMG why is cosmo brain a Rare card?
It's effect is ridiculous with protector,white stone, psychic ace and dragon spirt of white, a 3100 attack moster that allows slivers cry play and even if it get floodgated its 2450 defences is very strong, the OTK potential of this deck is ridiculous but the thing is you will likely lose if you go first, the game is sadly becoming a matter of coin flip! !
They are my favourite too and wont stop using them. Believe me, they will release mask change II sometime in the future to get people's money or release the so op Blackwings in a main box and all hell will break loose xD people will beg for the fur hire meta to come back lol