All in situation: weird rule online

I know that a thread on the same subject was made, but i can't find it (try searching all in and see how many results you get)
anyways on PS, for example, if you make a bet, someone pushes all in behind you and another calls, you can only call - no raise available
On most other sites you could come over the top to take the hand heads up against the all-in player, but on PS they only give you the option of calling the all in
what's the reasoning behind this?

Ok ill try to explain, its about re-opening the betting. The all in re-raise must be double the previous bet in order to be a valid bet to re-open the betting.

Example. Lets say the blinds are 500,1000

Tenbob- 256,590 in chips
Robwhufc- 90,000 chips
Chuck-T- 1,500 chips

Chuck T posts BB.... 1000 (leaving 500 chips)
Rob Posts SB... 500

Tenbob CALLS 1000
Robwhufc CALLS 500
CHUCK T Raise all-in.......... becuase the min raise in this situation to re-open the betting MUST be double the origional bet of 1000, then the betting is not re-opened, and the limpers only option is to call. They can then play a side pot on further betting rounds.

Hope this answers your question, i always find this one tricky to explain, i know there is an article on cardplayer somewhere in the archives about it.

ohhh i see i see
thanks tb that explains it

It is a sneaky rule that you can use to your advantage sometimes. Since you know the other person can't reraise, you can call without fear of it. In the right situations you can see a flop for a guaranteed price.

For the record, this is a regular rule we use at our local live tournaments and my homegames. It is not just an online rule, just one that does not come into play very often and most people don't think of until it happens to them. If nobody at the table knows about it in a live game, it can be missed and play goes on and nobody is the wiser.