I feel like I am more or less close to finishing the main quest but I haven't taken the time to close any gate other than the ones that are quest related. As such I've closed the one at Kvatch, Chorrol, Bruma (once, i think there may be another one coming) and also the one at cheydinhal. I used to hate the Oblivion realm but after a couple of hours(70 I think) playing the game I don't mind going there at times to change scenery. Furthermore there's gold to be made by goign into Oblivion gates. Anyways, as my topic says, once I finish the main quest, will all the OB gates close stopping me from going there at my whim?

Yes, once you complete the Main Quest, any open gates will close and no new ones will open.

Do gates open up randomly before that or are they all preset to be open at a specific time. im guessing the latter

Spoilers: http://uesp.net/wiki/Oblivion:Oblivion_Gates

exactly what I was looking for.
Thank you.

The locations are set, but with the exception of a few quest related gates, the rest are appear randomly.

Yes, all oblivion gates will shut once the main quest is completed.

Interestingly enough, no gates will ever open if you don′t hand in the amulet either. No one will die and nothing will be destroyed as part of the invasion as it will never begin. As far as I′m concerned this gives fuel to the saying; Don′t start nothing and you′ll get nothing

Actually, no gates will open if you don't pick up Martin
It's like nothing ever happened

Yes. You can close the Kvatch gate, save the city, become the Hero of Kvatch, and ignore Martin at the camp forever. No gates will open and no further Mythic Dawn activity will take place.

This is my favorite way of avoiding the Main Quest. Your character is free to come back at any time and resume the quest, should you feel the need.

Is that so? I usually go to Weynon Priory, take all at Jauffre's chest, sell it, then go. I'd love to get my hands on a sigil stone, or five.... I just didn't want gates all over my world. Plus the beat down I expect my Altmer Apprentice to receive within each gate. Here's a question, at what point in the MQ would the least amount of gates be opened?

The least amount of gates are open at the start of the game - the one at Kvatch. If you take Martin to Weynon Priory, then up to 25 more gates can open, but only if you go by the spot where one will spawn a time or two. At some point in the main quest, up to 50 gates can be open. Once you close a gate, it stays closed. The various gates at each city and the final one are in addition to the 50, IIRC.

The answer (zero) is at two points in the quest line. The first instance is just after the Kvatch gate is closed, and the other time is at the end of the Main Quest.

If you close the Kvatch gate, and never talk to Martin (you can do the whole battle for Kvatch if you want), you get one sigil stone, a couple of fame points, and no further worries about the Oblivion Crisis.

I thought this over again and came up with this: The question was: the least amount of gates “open”. If there are zero gates, then my logic says no gate can be open. One gate has to exist and be open to qualify being called “least amount open”. Otherwise, the question would be, “when are zero gates open?”

By the way, thanks for the tip on naming the save game files and making the text file. Very useful.

Oh goody. I will go then at level 17, for my one Oblivion Gate, and my one precious sigil stone.... my preciousssssssssssssss.

Ok, I didn′t know exactly when they started to pop up. I was so afraid it would happen and therefore I didn′t let my elf hand it in at all. Plus I was soooo occupied with everything else!

My first character completed the MQ, but my 2nd feels exactly this way and leaves the gates open and re-spawning on purpose. Many consider the gates a grind, and I also wish there were some more diversity in the layouts. But, my Breton Atronach role plays by using different strategies (beat the clock; leave nothing breathing; kill nothing and retrieve the stone) just for kicks. At level 30, with 91% absorption, she enjoys struting through them and hunting her victims down one by one. She no longer has a real need for the loot (already wealthy beyond reason), but enjoys the truly rare/exotic pieces and the stones. I guess the Christian in me never tires of closing the gates of hell. Such a rush. Much better than slaying dragons for me personally.

It's never too late to do the right thing, you know! That kindly old Emperor trusted you, saw something in you.

My first character completed the MQ, but my 2nd feels exactly this way and leaves the gates open and re-spawning on purpose. Many consider the gates a grind, and I also wish there were some more diversity in the layouts. But, my Breton Atronach role plays by using different strategies (beat the clock; leave nothing breathing; kill nothing and retrieve the stone) just for kicks. At level 30, with 91% absorption, she enjoys struting through them and hunting her victims down one by one. She no longer has a real need for the loot (already wealthy beyond reason), but enjoys the truly rare/exotic pieces and the stones. I guess the Christian in me never tires of closing the gates of hell. Such a rush. Much better than slaying dragons for me personally.

Who said my Dunmer didn′t do the right thing in the first place?

When I have characters that do the MQ, I mix up my approach to these gates as well. The sneaking without killing is really fun. Sometimes I run in guns blazing, sometimes I just want to sneak around. One time I ran in, got Harrada, which I was missing from a poison I was trying to make and ran back out again.

Agreed. But, all of this fun also reminds me that one of the saddest events my character experienced occurred deep within the nether tunnels of an Oblivion gate. It was simply business as usual until my character was startled by a noise. The "annoying fan" selected this unfortunate time and location to re-spawn from a previous death and re-join his grand champion. Unlike most characters, she really enjoyed his company and did her best to protect him. All she could do was look regretfully at him with a tear in her eye, knowing even all of her awesome skills could never get him out of that gate alive. Indeed, he perished permanently in her game within that gate. The gates can add an interesting twist to your adventures if you decide to tolerate them in your game.

Some of my characters have had things to say about what Captain Picard Uriel Septim could do with his Amulet. Consider that most of them are female. We start off with "I've been dreaming about a girl like you," and then it's "What's your sign, baby?" Finally he brings out the Bling.

What is the most efficient way to do this, early and fast if possible

Yeah he really knows how to pick up women