In how far does involvement in certain undertaking effects one, good or bad?

In how far does one take part on skilfull or unskilfull undertaking? In how far does one receives the fruits of good or bad actions by means of getting involved by toughts, signs and deeds, by assosiation with tendencies and certain objectives and aims? Are there even disadvantages, benefits, for one if just seeming for others to be near of certain undertakings? And how should common-kamma here be understood? *(Note that question in Dhamma is not dedicated for trade, exchange, stacks or entertainment but as a means to make merits toward release from this wheel)*