2019-01-25 : Effects that allow you to “cast” a card don’t allow you to play a land card.

2019-01-25 : If a spell has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.

2019-01-25 : If the chosen target becomes an illegal target for Electrodominance, the spell doesn’t resolve. You don’t get to cast a card from your hand.

2019-01-25 : If the target is dealt lethal damage this way, it will still be on the battlefield while you cast a card from your hand. It won’t die until after Electrodominance is entirely finished resolving. If any of its abilities trigger while you cast that spell, those abilities will trigger but won’t resolve until after the target has died.

2019-01-25 : If you cast a spell “without paying its mana cost,” you can’t choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, such as that of Bankrupt in Blood, those must be paid to cast the card.

2019-01-25 : You may cast a sorcery or permanent spell this way even if it’s not your turn.