Vlookup

where cell X1 is defined by a formula like: =if(A1="true"(B1="false"(C1="4x6", then "x")

Maybe:

Formula:

IF(AND(A1="true", B1="false", C1="4x6"), 2, 3)

would return a value of 2 if A1="true" and B1="false" and C1="4x6", otherwise it would return 3.

Or, to make it dependent on other cells on the row, for example,

Formula:

IF(AND(A1="true", B1="false", C1="4x6"), D1*E1, F1*G1)