“The fairest rules are those to which everyone would agree if they did not know how much power they would have.” — John Rawls
You being fair and honest in your negotiation efforts does not weaken your ability to defend your positions or advance your equitable interests.
What is the key to YOU getting your divorce case settled fairly?
YOU Be fair. To be fair, YOU be honest. Even if the opposing party is unfair and dishonest, you being fair and honest will do you no ultimate harm. Don’t misunderstand me: I am not advocating that you allow yourself to be hoodwinked or exploited (being fair and honest is not to be confused with being gullible or weak), but if you believe fighting the fire of lies and bad faith with fire is a recipe for your success in settlement, you’re sure to get burned.
Fair offers, based upon fact, are offers that, if rejected by your spouse, will be much harder for a judge to reject. Why? If out of self-interest (as opposed to the Golden Rule) your spouse rejects an objectively fair offer (i.e., an offer supported by facts), he/she has no obligation to justify his/her rejection that at the settlement phase.
But in trial you get to suggest to the court what its orders should be and why. An argument based upon unvarnished principles of fairness, backed by objective facts, naturally carries far more weight than an argument deriving from self-interest, unfairness, and fiction and/or a dearth of supporting fact.
I don’t place a great deal of faith in the court system, but I assure you that productively lying with impunity to a judge or trying to sell a judge as fair what is clearly inequitable is easier said than done.