Game Play Logic - ?playcard

In order to determine if a card is a "legal" move according to the rules of the Crazy 8s game, we developed this word, ?playcard. This word will place either true (-1) or false (0) on the stack.

: ?playcard
        dup
        13 mod 8 = if
                drop ( drop dup )
                true
        else
             discardpile
             lastcard
             dup
             8 = if
                getcardsuit
                swap
                getcardsuit
                = if
                        true
                else
                        false
                then
             else
                2dup
                13 mod
                swap
                13 mod
                = if               ( same rank/face )
                        drop drop       ( drop 2dup )
                        true
                else
                        getcardsuit
                        swap
                        getcardsuit
                        = if                         ( same suit )
                                true
                        else
                                false
                        then
                then
             then
        then
        ;