Texas Hold'em tournament strategies
Texas Hold'em tournaments are where the biggest cash prices can be found in poker. The biggest open tournaments are worth several millions to the winner and the World Series of Poker (WSOP) Main Event nowadays awards the winner with somewhere around 10 million USD ( 8.7 million in 2011, 12 million in 2006). There is plenty of money to be made in cash games as well and most players do make more money from cash games than they do from tournaments, but the tournaments still offer the best single payouts.
Playing both cash games (also known as ring games) and tournaments will make you a stronger all around player and you should therefore consider playing both. Tournament games have a very different dynamic than cash games and require a very different strategy. Also, different stages of the tournament will require different strategies - strategies that will be effected by the size of your stack.
In the beginning of the tournament, the blinds will be low and you should (depending on the opponents off course) play rather tight and play primarily strong hands. It is usually a bad idea to risk everything on a mediocre hand early in the competition as there is plenty of time to get your money into the middle in a better situation. As the tournament progresses and the blinds go higher, you need to start playing ever more aggressively. On high levels even mediocre hands is to be considered strong and that is why the poker you see when watching tournaments on TV seem incredible aggressive (and why copying the style you see used there on cash games is usually a bad idea since the dynamic is different when your opponents can afford to wait for good cards before they take you on).
Stack management is also essential for your tournament strategy. If you are getting low on funds in a tournament, especially a bit in, you will need to be a lot more aggressive than you would be in a cash game because otherwise the blinds will eat you up. If you are down to a few blinds you will need to take a chance on any half decent cards and go all in.
If you on the other hand is sitting with a big stack towards the end of the tournament then you can afford be a bit more selective choosing what hands to play, but it can of course also be a great time to become aggressive as you might be able to steal blinds and bully low stacked players. Which is the better strategy is largely due to the stacks of the other players at the table. If the other players are low stacked it might be worth trying to bully them, but if the table is shared with a lot of other high stacked players it might be good to be more selective.
To conclude, tournament games are a lot like ring games but with certain other factors involved that need to be considered. This is due to the fact that the game largely remains the same when playing in a ring game, i.e. the blinds remain the same and when you run out of money you do a re-buy to get more chips. In a tournament, the game is always evolving and changing into something else which means that you need to adapt to different game situations in a whole different way than in a cash game. Being a good cash game player is a good start on the road to becoming a good tournament player, but you need to keep in mind how the tournament format adds new aspects to the game that you must consider and master to become a successful tournament player.