The Collaborative International Dictionary of English v.0.48:

Rascality \Ras*cal"i*ty\ (r[a^]s*k[a^]l"[i^]*t[y^]), n.; pl.
   Rascalities (r[a^]s*k[a^]l"[i^]*t[i^]z)
   [1913 Webster]
   1. The quality or state of being rascally, or a rascal; mean
      trickishness or dishonesty; base fraud.
      [1913 Webster]

   2. The poorer and lower classes of people. [Obs.]
      [1913 Webster]

            The chief heads of their clans with their several
            rascalities                           --T. Jackson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

rascality
    n 1: the trait of indulging in disreputable pranks [syn:
         prankishness, rascality, roguishness]
    2: the quality of being a slippery rascal [syn: rascality,
       shiftiness, slipperiness, trickiness]
    3: reckless or malicious behavior that causes discomfort or
       annoyance in others [syn: mischief, mischief-making,
       mischievousness, deviltry, devilry, devilment,
       rascality, roguery, roguishness, shenanigan]

The Devil's Dictionary (1881-1906):

RASCALITY, n.  Stupidity militant.  The activity of a clouded
intellect.