We start with one of the least common decisions, but it is appropriate to begin with surrender, because this decision must be made before any other choice about playing your Blackjack hand. Not every game offers surrender, and those that do fall into two categories, which bear explanation: Early vs. Late. In Blackjack, surrender offers you as a player the choice to fold your hand, at the cost of half of the original bet. You must make that decision prior to taking any other action on the Blackjack hand. For example, once you draw a third card, or split, or double down, surrender is no longer an option.

The two varieties of surrender, early and late, differ only in the way a dealer Blackjack is handled. In an early surrender game, a player may choose to surrender before the dealer checks his cards for a Blackjack, offering a cheap way out even if the dealer turns out to have a Blackjack. Because this offers a healthy advantage to the player, this version (early surrender) is rarely offered. The much more common variation is late surrender, where the dealer checks for Blackjack first, and then only if he does not have Blackjack will allow players to surrender their hands.

Surrender is a nice rule to have available for Blackjack players who use it wisely. Unfortunately, many players surrender far too many hands. To see how bad a hand must be to properly be surrendered, consider the following: To lose less with surrender, you must be only 25% likely to win the hand (ignoring pushes). That is, if you lose 75% of the time, and win only 25% of the time, your net loss is about 50% of your bets, equal to the amount you'll lose guaranteed by surrendering. So, learn to use the surrender option, but make sure you know when it is appropriate.
It's worth mentioning again that the vast majority of surrender is LATE surrender, after the dealer checks for Blackjack.