Take Grindstone, for example
Ill-Tempered Loner + Angelfire Ignition Thankfully both the day and nightbound sides of Ill-Tempered LonerHowlpack Avenger function the same for this combo
Whenever a land is tapped for mana, return it to its owner's hand.
Like attacking and activating other abilities, mana production is a vital part of the game
If a creature can't attack for any reason (such as being tapped or having come under that player's control that turn), then it doesn't attack
They're a topic that generates a lot of impassioned discussion, mostly because every time they come up, everyone starts arguing about the affordability of Magic and how WotC makes the game too expensive to play. There is increasing acceptance of proxies in certain situations , especially provided you are not trying to use fake cards and pass them off as real or using them in tournaments where they're not allowed