I know this post hasn't seen the light of day in some time, but this is such an interesting subject I just had to say something.
Here are a list of my favorite and least favorite TCG mechanics:
Least Favorite:
-Resources as part of the deck: I mean games like Magic: The Gathering where you have to pull the resource as a card and ONLY that card can be used as a resource. It lends itself to things like "not enough resources" or "too many resources in hand" (of course in Magic terms, it's "Mana Flood" and "Mana Starved").
-Not really a bad mechanic, but the fact that "tap" is copyrighted. Designers are forced to use terms like "bow", "kneel", "exhaust", "use", "boot", or "bend over and give it to me". We all say "tap", it's dumb that someone decided to copyright it.
-Rock/Paper/Scissors reveal: This is used in games like Yomi where players place down their card and reveal. It's not really what I call...strategic as much as it's called "dumb luck". Yes, there's an element of luck in conflict, but making it so obscure as rock/paper/scissors is dumb in my opinion. Games like War of the Indines feel better; it's not as simple as rock/paper/scissors and it give more of an element of strategy.
-Overly complex mechanics: I love games like Legend of the Five Rings, but there are times when it got so complicated, I just soured on the game. They've streamlined it since then, but just streamlined enough to get me interested again. "Keep it simple, stupid" is what my mentor would say.
-Extremely beautiful card art, but the gameplay is too simple/lacks depth. I've seen this in games like Exodus and Blue Moon Legends. The art: amazing, but the art doesn't match the gameplay. It's almost as if the art is more important than the game itself. In Exodus, most creatures are the same, there's no difference between creatures statistically other than what you put into it. Blue Moon is just a one-up game at its core. If you have the wrong cards to one-up the opponent, you lose.
-Draw 1 card at the beginning of your turn: I don't like this one bit. It lends itself to top-decking (using up all your cards to the play field and you're relying on the top draw card to play every turn) and that's a bad position to be in. Have players redraw to a hand size...or at least draw 2 cards. It severely limits the amount of options a player has. Yes, I know there are card powers that mitigate this, but drawing only 1 card is too limiting.
-Deck Building: I only say this because it's what I don't like at this moment. The idea of deck building is pretty smart, it's the fact that EVERYONE AND THEIR BROTHER IS MAKING A DECK BUILDING GAME! I'm going to wait a long time before I decide I want to make a deck building game.
-Rares: While a great way for card companies to make money, having rares in a card game has opened up a whole middle and black market on card games. Of course, this is something that's evolved over the course of time; I don't think Wizards of the Coast had this in mind when they made Magic: The Gathering. But it's an inevitable truth nowadays: you CAN buy your way to victory.
I know some of these things aren't exactly "mechanics", but it's stuff I find really irritating.
Now onto my favorite mechanics in TCGs:
-Fully customizable but randomized deck: We can engineer our decks any way we want. it's the order in which these cards come out that make each game exciting.
-Instant cards: Cards that make you say "a HA!" These are surprise strategies that can turn the tide of battle. It's that wild card you save in your hand that keeps you alive for that one turn you can beat your opponent.
-Multi-purpose cards: Not only are certain cards used for 1 singular task, but a secondary task as well...even a tertiary one. It gives versatility and options to the player. It can be as simple as "do X or Y" or "Do X, but in another situation, it can do Y".
-Tap or "use"; reorienting a card to utilize its power. Yes, I said the word tap is messed up, but the usage of a card by reorienting it is a brilliant mechanic. Some have taken it to the next level by giving meaning to which orientation the card is turned.
-Any card can be used as a resource: If there's anything that stalls some games it's resource acquisition. When any card can be used as a resource (a la World of Warcraft TCG), then it's up to the player whether or not they want to create a resource or play a card. It gives more control to the player and that's a good thing.
-Event cards: This is really evident in Game of Thrones LCG. It creates a scenario in which the players have to conform to, which forces the players to rethink their strategies constantly. Both players may know what cards the other player has in their deck, but the event cards really change things up.
-Character Cards: This is really great for the designer. It forces the player to conform to a set stat structure that the designer has put forth. It's more control for the designer, but forces the player to be more creative in their execution. Pathfinder ACG is a great example.
-Turn Order Card: This isn't really a mechanic as much as it is a great reference. Star Wars LCG has it but Lord of the Rings LCG doesn't? Weird. Sometimes we get so caught up in the game that we forget there's a turn order we must abide by. A game could go in a very weird direction when someone misses a step, which is almost imperative a turn order card for reference is needed.
-Reshuffing, then putting it on TOP of the deck. This is evident in Pandemic. It forces a timer on the game and it's designed so that the trouble areas only get in more trouble. Brilliant.
I'm sure there's more, but I'm going to keep it at this. I hope this will get the discussion going again as card games are my favorite.