Reckless aggression is a frequent mistake when holding Ace King. In particular by those players who do not understand how vulnerable this hand can be. Invariably in online poker tourneys whenever someone in a hand is holding ace king you are likely going to either witness or take part in an big pot.
What a lot of players do not understand is that AK is a drawing hand that rather incessantly needs to improve in order to play a big pot. The way you play Ace King has a lot to do with circumstances in the tournament. For example, it is really not wrong to shove pre-flop when you are short stacked because with AK you are almost never in bad shape against anyone who calls you. There are certainly only two hands that you do not want to see flip over - pocket aces or pocket kings. Anything else and you are at worst a slight underdog against a single opponent.
But there are a lot of situations where ace king should be playing with caution. Early in the tournament, even with a hand as strong as ace king you still want to keep the pot small without the board has really helped you. Top pair and top kicker is a decent hand, but it's not necessarily a hand that you want to let your tournament ride on in the low blind levels. So if you do hit an ace or a king on the flop you are very reasonably leading, but if your opposites decide to hang around you need to be very concerned about straights, two pair, flushes and three of a kind. In fact, on a dangerous board in the early stages you may have to consider folding your top pair hand if the pot gets out of control.
If you have your opponent out-of-position pre-flop, but you hit nothing but air, he may very well put out a feel bet to see what you will do. Then all of a sudden you've got a difficult choice to make because you will be calling with an ace-high hand. If you think about it, AK is really a hand that you want to see all five cards, because you have a very good chance of hitting the turn or river and making the best hand. However, if you hit nothing on a ragged flop, you're almost always going to be involved in a contentious situation. That is something you want to nullify in early tournament levels, as well as against hostile players.
There is also another consideration because I also like to play AK cautiously if there are several limpers before me. True, you could raise and narrow the field but with multiple players interested in the pot, my tension is to think that they are also holding high cards too, further depleting my chances of hitting the flop. If you are not short stacked, try and get to see a cheap flop that helps you, then bet out. Depending on what your opposition does can influence your play for fourth and fifth streets. That's when opposed profiling can come into play too. Ideally you want to keep Ace King a paying hand for you, and only play big pots with strong flops.