Don't be too greedy: Early closed borders can hurt.

[Pinstar]

I started on a landbridge about 3 tiles wide. In front of me was the Japanese, behind me was a jungle chuck full of luxuries and food resources. The island was almost pure jungle, and not worth settling in the early early game. Instead, I expanded up along the coast of the main land, nabbing wine and iron resources before the japanese got to them.

As soon as I discovered writing, I was asked to open borders...and promptly said no. Soon explorers from 4 other civs came knocking at my door, and I turned everybody away.

Scrolling through the civs, EVERYBODY was "annoyed" with me, except Washington...he was a world away and I decided to open borders for him.

In the end, 3 civs declared war on me and promptly trashed me...


When you get that first request for open borders, think twice about saying no.

On the other hand, if you want to keep your borders closed for longer without having the diplomatic penalty, just hold off on researching writing.

 

[DisruptiveIdiot]

Or you could keep them on good terms in other ways, such as opening trade deals. Open borders is basically saying "screw off!", so you have to counter that message. Changing state religions can do this, as can bribes (though that is not advised). If you want closed borders, you'll have to make concessions in other areas.

 

[Life]

I say choke your opponents and keep your borders closed. The idea is to limit the resources and land your opponent can get while you expand and bring your civ up to be more powerful. If you use the closed borders to your advantage, there won't be any civs near enough to you to be a major threat. I've been on friendly terms with a civilization that was next to my border that I kept on denying open borders with. I highly doubt keeping your borders closed was the reason why three civs declared war on you. Perhaps you were a little too tough with handing out resources or tech? Or maybe you were just too great of a heathen in their eyes and were trading with their enemies. Open borders is probably only helpful when you have all the land and resources you want safely within your own cultural boundries.