Human relationships can be very challenging. People frequently want different things from each other and can enter into both professional and personal relationships with differing expectations. Some people complicate these issues by having hidden agendas and by saying one thing but doing another. These so-called 'mind games' are frustrating and can be challenging to deal with. Discipline is needed in not allowing these types of people to negatively affect your life.
Identify the other person's objectives. This can be challenging but if there is a co-worker who is friendly to you in person but talks about you behind your back, he may be trying to get a promotion or make himself look more appealing to other workers to get ahead. A boyfriend who suddenly disappears may have only wanted a physical relationship. If you can determine what the other person wants, it is easier to decide on course of action.
Prevent a reaction. Some people manipulate others for the satisfaction of getting a strong response from them. By not providing a visible response of anger or frustration, the appeal of the "game" may go away and the person will move on to easier targets.
Question the person directly. In a calm and professional tone, ask the person why he acts the way he does. Avoid an emotional conversation (even if it is a romantic partner) and keep the discussion intellectual and see if the other person can provide any insight or honest answers.
Limit your contact. If someone continues to try to manipulate you, cut off her access to you as much as possible. In a professional environment, only be around her when you have to work with her. Cut off friendships or romantic relationships if you feel the other person is playing games with you. The alleviated stress in the long run will be worth the temporary emotional pain that may result.