Fire Arrow is a simple but great card, useful in a multitude of situations. Costing only 1 red energy, it can be played on your first turn, dealing 2 damage to whoever you see fit. However, unless necessary, don’t play Fire Arrow right away-- instead, bench it and play it as soon as your opponent plays a card. This is simply because of Fire Arrow’s low damage count; if you play it on your very first turn and deal 2 damage directly to your opponent, it won’t do much. On the other hand, when used on an opponent’s ally, it can potentially save you a few HP and at the same time get rid of an opponent’s ally, clearing up the field for you. Also, if you draw Fire Arrow later in the game, use it wisely-- it may save you, finish off your opponent, or both.
Weak against: High-HP allies, slow-developing decks (in slow decks, allies tend to have higher HP. On the other hand, when playing against a slow deck, Fire Arrow might help you win-- don’t get rid of it!)