Stone Strike is entirely dependant on AC
(Taken from
http://tricksterwiki.sakura.ne.jp/in...B6%B3%D0%B7%BF)
* AAM on-target impact on-target hit ratio =72+MOB evasion ×2.5 (fractions omission)
In english, this meas you need 72 AC to hit a monster with 0 HV, 100% of the time.
For every additional HV the target has, you need 2.5 AC to maintain 100% hit chance(rounded down).