Do you feel that someone is continually taking advantage of you? Do you seem to have to fight your corner aggressively, or ally with others, to win the resources you need? Or do you struggle to get what you want from people whose help you need, but over whom you have little direct authority? If so, you may need to brush up your win-win negotiation skills.
Effective negotiation helps you to resolve situations where what you want conflicts with what someone else wants. The aim of win-win negotiation is to find a solution that is acceptable to both parties, and leaves both parties feeling that they've won, in some way, after the event.
There are different styles of negotiation, depending on circumstances.
Where you do not expect to deal with people ever again and you do not need their goodwill, then it may be appropriate to "play hardball", seeking to win a negotiation while the other person loses out. Many people go through this when they buy or sell a house – this is why house-buying can be such a confrontational and unpleasant experience.
Similarly, where there is a great deal at stake in a negotiation, then it may be appropriate to prepare in detail and legitimate "gamesmanship" to gain advantage. Anyone who has been involved with large sales negotiations will be familiar with this.
Neither of these approaches is usually much good for resolving disputes with people with whom you have an ongoing relationship: If one person plays hardball, then this disadvantages the other person – this may, quite fairly, lead to reprisal later. Similarly, using tricks and manipulation during a negotiation can undermine trust and damage teamwork. While a manipulative person may not get caught out if negotiation is infrequent, this is not the case when people work together routinely. Here, honesty and openness are almost always the best policies.