In blackjack, you should always split aces when you are dealt a pair. Splitting aces gives you the opportunity to form two strong hands, each starting with an ace, which can potentially lead to a winning hand of 21 if you draw a ten-value card on either. This strategy maximizes your chances of improving your position against the dealer, as aces are highly valuable in the game. While you will only receive one additional card on each ace after splitting, the overall advantage you gain from splitting aces makes it a fundamental strategy in blackjack.