In general, if two or more hands are tied, the winner is determined by the higher card (i.e. a pair of Aces beats a pair of Kings). If the hand remains tied (i.e. a Pair of Kings vs. a Pair of Kings), then the winner is determined by the "Kicker", the highest extra card in the hand.
If hands are identical, the pot is split evenly, with odd chips going to the first winning player to the left of the dealer.
Hi-Lo poker variations work a bit differently - for further details, please click here.