"搞骗人的玩意" can be translated into English as "engage in deceptive tricks" or "play fraudulent schemes".
Here are two example sentences to illustrate the usage:
1、 Don't engage in deceptive tricks to cheat others; it's unethical. (别搞骗人的玩意去坑别人,这很不道德。)
2、 He was caught playing fraudulent schemes and lost his reputation. (他搞骗人的玩意被抓了个现行,名声也毁了。)