What if They Use Dirty Tricks?
A bad negotiation can destroy a relationship. Don’t let your emotions flair at the first sight of an unpleasant technique being used. Thy are using a technique because because the negotiation is important to them too.
You can point out the technique. This alone can be enough to get the discussion back on track. You can ask for factual clarification of their position. This will give you more information about where they stand and could make them realize their position is unreasonable. If things get bad enough, you can always walk away. Have your next best alternative ready. Bring it up first. Not as a threat but as a possible outcome if the negotiation falls through.
Don’t be a victim in a negotiation. As long as you make a factual and principled argument, you have the upper hand. Facts are easier to defend than positions.
Book: Getting to Yes