In this game only correct letters in the correct places were counted. For example IDEAL and CEDAR:
1) "I" is not equal "C"
2) "D" is not equal "E"
3) "E" is not equal "D"
4) "A" = "A"
5) "L" is not equal "R"
That is, the letters D and E were present in CEDAR, but they were not count.