Tip # 11 of 52, You are generally receiving good odds on your hand when faced with calling half a bet in the small blind.
Suppose three players have called the initial bet. You are in the small blind with half a bet in. What price are you receiving from the pot on this call? You must put in half a bet, and the pot contains nine half-bets (including the big blind and your small blind) already. So, the pot is laying you a price of 9-to-1. This means you must win only 1 time in 10 for calling to be correct, assuming no additional betting. However, there is additional betting, and your positional disadvantage should also be considered here. Therefore, you should be holding a halfway decent hand to complete the bet.
A broad range of hands are worth a call, though. Any two suited cards will do, as well as any hand containing an ace. Also, any two connecting cards 9-8 or higher are worth a call. Hands with one gap (cards not adjacent in rank, but separated by one rank) smaller than Q-T should typically be folded (T-8, for example). Any pair is playable from the small blind. Some of these hands need to be hit pretty solidly by the flop for you to continue, but they do possess the potential to develop into big hands.
The preceding guidelines apply to games with a 1-2 chip blind structure (such as the $1 and $2 blinds in a $2-$4 game or $3 and $6 in a $6-$12 game), in which the small blind is exactly half the amount of the big blind. However, you may find yourself in a game with either a 1-3 or 2-3 structure. This has a huge effect on how the small blind should be played.
For 1-3 chip games, treat the small blind as you would a late position hand. If the hand isn't worth a full bet from late position, it isn't worth two-thirds of a bet from the small blind. Of the types of hands listed earlier as playable, suited trash and bad aces should now be folded, as should connectors such as 9-8 and T-9 offsuit. Small pairs are still worth a call, as are medium to large suited connectors.
In 2-3 chip games, playing the small blind is incredibly simple. If two or more players have called, you should call with everything! Yes, even 7-2 offsuit* is worth an extra chip in this spot. Just Don't get carried away if you flop a deuce. The time to consider folding the small blind for one-third of a bet is when only one player has called, you are holding a bad hand, and the big blind is a frequent raiser. As long as those conditions aren't all there, though, you should put in the extra chip.