I play a lot of 5/6 person .25/.50 NL and .50/1.00 NL...and I almost NEVER limp aces and kings.

Why, you ask? Because you allow junky hands to see a flop from the blinds and outdraw you. You wouldn't believe the number of times I've busted AA from the blinds by flopping 2 pair.

Aces will limp, I'll have K7o from the BB and see a free flop...K73 comes, I go all-in, aces calls, then aces proceeds to cry about it in the chat window.

If someone insists on seeing a flop with junk, you've got to make them pay to see it when you have aces. At a NL table, the minimum bet I make preflop with AA, KK or QQ is 3 bucks, and depending on the play of the table, it may be more...

Sometimes, if can payoff to limp when a maniac has made a big raise preflop and everyone else has folded, but chances are if he's got a hand he likes since he made such a big bet and will go all-in with you if you go ahead and push right there.

Now, if I'm playing against a *good* player who raised ahead of me when I had aces, I'm going to push him back hard. Let's say he raises 2 bucks ahead of me, I'm going to make it 6 bucks to go. You're either going to force him to pay 4 more bucks to see a hands he seemingly already likes, or you're going to take his 2 dollars right there and be done with it.

The less people there are at the table, the "safer" it is to limp aces...but I never really consider limping aces to be safe.