At the beginning of every game, the initial position is determined randomly. The pieces are set up symmetric like in usual backgammon, i.e. if white has n pieces on point x, then black has n pieces on point 25-x.
Besides from this, there can be various detailed rules to set up the pieces. The following is an example:
There is no blot (single stone on a point). every player has 15 pieces like in normal Backgammon. Every player has at least 2 stones in every quarter of the board. The rearmost stones of a player are not passed by any opponent's stones (i.e. if the white rearmost stones are on point 4, then there are no black on points 1 to 3).
All other rules are the same as in standard Backgammon.