Yes, for most of the online contests, number of wrong submissions contribute to penalty.

More wrong submissions, the lower placing you gonna get, despite solving the same number of problems in the same period of time.

But for some of the OI contests (e.g. IOI), it is fully based on scores only and completely ignoring the number of wrong submissions.

I know that codeforces style (ICPC style) has this penalty system, but if you are given the choice, which would you choose?