from the introduction:
Blackmail details System Reference Document v.3.5 set & setting rules for game judges. This booklet is also adjusted to incorporate the 1e racial & class abilities in lieu of “skills” & “skill checks” from 3e. With the four S.R.D. of the All Mind booklets plus Words of Spells and Blackmail a judge has all the mechanical rules needed (otherwise found in a 3e version) to use the Knights of the All Mind supplement.