A big part of getting people on your side is negotiating. Whether you’re agreeing a business deal, arranging with your siblings to share care of your elderly parents, asking your boss for a pay rise, agreeing bedtime with your child, or splitting the bill after a meal out with friends, you need to know how the other person is feeling and what will make them want to co-operate with you. And the good news is that almost everyone has the same basic criterion when they’re negotiating.

Everyone wants to win. Simple, really. Let them come out on top and they’ll be happy to agree the deal.

You’ll have spotted a flaw in this approach. Yep – if they win, where does that leave you? Well, that’s the interesting bit. If you play your cards right, you can win too. And that should be your aim in any negotiation. In fact, it’s the only outcome that can possibly work.

Think of a simple business deal. Let’s say a market trader selling to a customer. As it’s a market stall, the customer isn’t going to pay the asking price. They’re going to haggle. So it’s become a negotiation, albeit of the most basic kind. You’ve been in this situation yourself I’m sure, and what generally happens is that you agree a price somewhere in the middle. So who’s won? Well, you have of course. You’ve got the item at a price you consider worth it – if you hadn’t, you’d have walked away. But hang on, the stallholder didn’t have to accept your offer. They could have refused to sell you the thing. So they must be feeling like a winner too, if they agreed to the deal.

And that’s what you’re after. As you may know, this is known as a win/win deal. And it doesn’t only apply to business deals and money transactions. It applies to any agreement you’re trying to reach, with your friends, colleagues, family, kids, neighbours.

Let’s go back to your kids’ bedtime. You could just tell them it’s 8pm and you don’t want to hear any argument. However, as they get older, you’re likely to want to allow them some input, without allowing them free rein over when they go to bed. It’s good for them to start learning to regulate their own timetable. Then again, you don’t want it to turn into a row followed by a long sulk, or a rebellion, when they feel you’ve won the argument and they’ve lost it. Look, they know you’re not going to let them go to bed at 2am. They’re expecting some kind of limit, broadly in line with where you’ve drawn the line when they were younger. Which means it really should be possible to strike a deal where you both feel you’ve got what you want – so that should be your aim.

The next few Rules will help you fine-tune your negotiating antennae so you can turn all your deals into win/win ones. Yes, even when you’re negotiating with your kids. Understand what they’re looking for and how they think, and it becomes much easier to work with, not against, each other.