Good cop / bad cop can also be used in real estate negotiations.

My agent was ‘good cop’ presenting my hardball offers – I was ‘bad cop’ (the unreasonable buyer/seller) asking for things I knew the seller/buyer wouldn’t agree to and telling the seller/buyer (via my agent) to F-off inre anything they asked for.

During purchases, a key piece of this strategy was letting the seller know that I was a serious / qualified buyer and that if we reached an agreement, we WOULD be closing escrow.

As other posters have stated, you have to negotiate from a position of strength. The main part of this strength is being willing to walk away from the deal – if you aren’t willing to walk away from the deal you have given up most of your negotiating power.