To broad of a question. BI, tournament type, blinds, position, type of players at table, your image, etc. The list goes on forever. Give us a certain hand with details and we can help!
Some of the replies...well most of the advice in here has me shaking my head, putting my palm to my face, and repeating this action. -__-
Trying to answer objectively and provide as much genuine/logical information as possible based solely on what was given. There are definitely hand specifics that would change the situation and help us refine the advice we give out here but all I know is OP asked about inner logic and deciding lines of play whenever he sees A2s.
I'll list what seems the most popular opinions so far (with brief explanation feel free to correct me if you want):
Fold this hand at a full table (like 8-9 players) because you can suspect another Ace to be in the field against you. OF COURSE you can get fancy feeling and raise large to make the stronger Ace fold but if you are called you will not know if you were successful.
Fold this hand in early position since you haven't seen anyone act and you can't call a shove or even raises OOP with this hand. For the same reason...
Don't limp with it
If you are limping in early position at a full table you are usually handing away free chips. If you are in late position and you know you want to play this hand (maybe short-handed or just feeling loose and lucky?) you DEFINITELY want to raise to see where you are and to take the lead in the hand which will win you the pot a lot more often when your opponents don't hit the flop either.
This is one of those long-term
expected value propositions. I cannot see limping from late position to be a profitable line of play with A2s. I think you will lose plenty more often than you win with this strategy.
I'll also reiterate here the straight outs are very weak, even in a raised pot. I'll call raised pots with good odds with a hand like 56/67s knowing that I can stomp the wheel if it presents itself on the board or I think my opponent has the lower straight. If you limp you invite those hands that potentially destroy you. The nut flush is not a common occurrence. I can't count on it or predict it reliably so I need another way to win the hand just in case if I can.
Finally, like quoted poster suggests,
use ALL the information at the table that you can. Nothing is set in stone, you will find other ways/times to play this hand if some certain situation compels you.
Gotta trust your gut and just win those hands, even if the hand is 32s and you just pretend that its an Ace.