trickiness

from WordNet (r) 3.0 (2006)

trickiness
    n 1: the quality of being a slippery rascal [syn: {rascality},
         {shiftiness}, {slipperiness}, {trickiness}]
    2: the quality of requiring skill or caution; "these puzzles are
       famous for their trickiness"

from The Collaborative International Dictionary of English v.0.48

Trickiness \Trick"i*ness\, n.
   The quality of being tricky.
   [1913 Webster]