I just bought a guitar a few days ago. Never played before, so I have 0 experience haha
But, I'm wondering how long it would probably take for me to play decently? Not trying to be the next guitar virtuoso or anything. Just decent enough to play straight forward, raw death metal.

There's no proper time frame for how long it takes you to get to a vaguely defined point. Work out a practice schedule, have a teacher or experienced/trained guitarist make sure your technique is good, and you'll continually improve. There's no point that you'll get to where you'll suddenly be decent, and once you get there, you should still be practicing. There are a lot of different things to learn, and they've been mentioned countless times before. Search this forum, ask questions if you can't find answers or you need clarification, but try to ask about specific things.

Raw Death Metal? Just tune to drop C and do bar chords in time. You should be good to go at that point.

But in all seriousness, there is no static amount of time it takes to become a great musician. Some people have been playing for 30 years and suck. While bands like decapitated put out their first album when they were like what 16? It's all depending on your creativity and natural talent.

Just start chugging and playing everyday and eventually you'll start playing something you like and enjoy that you would consider where you want to be. I've been playing guitar for 15 years and I don't feel I know a goddamn thing about it I just know what I like and can play easily.

Echoing what's already been said, but to get the most out of playing guitar, learn to play what you like listening to.

That question is highly dependent on a lot of different factors. How old you are now has a lot to do with time frame of learning a new skill. Also, the amount of free time you have to practice. Finally, what you are hoping to achieve in a certain time frame, as "raw death metal" is not as simple as you may think.

My best answer is anywhere from 1 1/2 to 6 years. If you are like 12 or 13 and can practice 8 hours a day, 1 1/2 years is a pretty reasonable frame to be able to properly start playing some stuff like Asphyx or early Death. If you are like 18+ are in college, have a full time job, wife, kids, or anything like that, it may take up to 6 years if you dont have the time to actually play guitar.

Personally I've learned taking lessons helps speed things up alot. Having someone who knows how to play guitar teach you and show you how to play really helps, and doing this on a weekly basis will help you improve gradually. I took the level 1 and 3 classes at old town school, then moved into a teen band class for a while, and now im taking jazz lessons. This week to week playing has helped me greatly, and every week I have noticed improvements, especially with the jazz classes. Now even if you can only afford a few sessions of entry level lessons, find another guitarist, bassist, or drummer, and just jam to get that practice in on a weekly basis, you will see improvement.

It will take 13 years, 24 weeks, 1 day, 3 hours and 15 minutes.

And 42 seconds.

I agree with everyone who isn't trying to (good naturedly *fingers crossed*) take the piss. I feel like it's pretty much everything here combined. Learning in whatever way works for your circumstances (with no money for classes, I used a beginning exercise book after years of no technique and improved leaps and bounds ... fml of wasted time) doesn't mean shit if you don't play almost every day. David Gilmore, so far as I know, didn't know how to read music for most of his career (if that ever changed) and that guy's fucking amazing. And there are lots of self-taught metal wrights of awesome. Diligent practice and the willingness to power through the terribly awkward phases of the learning curve will serve you pricelessly. Stay dedicated and you'll improve really fast. Procrastinate and you WILL stagnate.

I've been playing for like one year, I can record what I need for music I've previously written (and recorded by another guitarist). But in general I feel that I suck with guitar in general, I barely can play Master of Puppets intro and main riffs, some people achieved some shredding techniques with one year, It's really about how much practicing and concentration through practicing you put into it, be patient, try to get a teacher and learn techniques rather than songs (not 100% like this, but techniques and practicing should be more than playing songs).
good luck

Two years

Here's a tip: Jam with guys who are better than you, or get a teacher. For about two years all I did was play guitar in my bedroom and while I could make sounds that sounded SOMETHING like the stuff I liked(Megadeth, Death, Bolt Thrower), things like more precise timing, making that pinch harmonic really scream, playing solos cleanly or making your chugging actually heavy, all these finer details that separate the bedroom guitarist from the actual musician were missed out because I had no proper critique from an experienced eye. I've learnt all these in the space of a few months after getting a teacher and joining a proper band(the one in my sig).

Honestly, despite all the great info here and in other similar topics, it depends on the person. Some people will pick it up faster, some more slowly. I don't think you can give yourself a time-frame.

Start watching tip videos that really good guitarists make and practice good technique. Play without distortion until you have your technique down. Then just keep playing until you are where you want to be. The amount of time is really just going to depend on how dedicated you are and your natural skill. It will certainly help if you can dedicated a couple hours a night for a good while.

You should find something that you enjoy playing, and practise that. Try all kinds of stuff and see what sticks. Make it fun and don't force yourself!

Totally different for everybody. I've seen people get stupid-good at that shred-wankery nonsense within a year. That being said, I don't consider that proper guitar playing. You could learn very quickly or you could take an eternity. Its all in your head. Best thing you can do is record yourself playing from time to time, listen to what you are doing and critique it a couple hours later.

I've been messing with the guitar for 20+ years and I still can't play. Oh, to non-guitarists it might sound like I can play. But make no mistake, I suck. Yeah, I can play some Metallica, Sabbath, Led Zeppelin, fingerpick acoustic stuff like The Beatles "Blackbird" and Fleetwood Mac's "Landslide", do tremolo picking, even play Eruption by Van Halen (it's easier than it sounds), but I can't play these super fast thrash rhythms without mistakes, and forget about things like arpeggios, sweep picking, etc. And I practiced a lot in the beginning. My ultimate goal was to play like Michael Angelo on his Speed Kills instructional DVD. I improved from watching it, but I never came close.

Some people have it, some don't. But if you enjoy what you CAN play, you'll still have fun. Every song learned gives you a boost.

I figure it'll take you 6 months to start being able to play most of a worthwhile full song.

Oh, and make sure that guitar you've got is a good one. My first attempt was on a Sears guitar and I thought I couldn't play because the strings were hard to press and buzzed so bad. Years later I rented a cheap Fender Squire and it made all the difference in the world.

Just be sure to make it over that "learning hump". When you first start, it'll be difficult to make yourself play, tedious even, because you suck. Just learn a lot of easy songs to keep yourself interested, and then you'll be completely addicted to it.

Best advice I can ever give is never stop trying to play stuff that's out of your league. When I went through the learning process of both guitar and drums, I would usually shoot for stuff higher than what I was at and the result was me learning fast. I've already learned drums and I'm really good at them, but I'm still learning guitar. And I've consciously noticed that whenever I learn songs and get comfortable with them and play those same songs every time I have a guitar session, I don't get any better. I get better when I try learning a riff in a song that is too fast for me to even mentally think about what I have to do.

Very good advice. I feel you should always push your limit in terms of speed. That being said, I also think it's important to not move on to more difficult songs until you can NAIL your comfortable songs in terms of tightness and sound(picking dynamics and feel). Before I joined a proper, professional band, I THOUGHT I could play Pure Evil(Iced Earth). After months of drilling(and being yelled at), I randomly went back to the song and found my chugging and triplets to be MUCH clearer and tighter. Hell, I even saw improvements when playing Master Of Puppets.

Same with me, except I'm not as far as you. Now I try playing some thrashier songs where as I go back to a pop punk song I used to learn and noticed that chord transitions aren't difficult anymore. Or that song with the temolo picking doesn't seem as fast.

I'm not a particularly good player, but I focus on being tighter and heavier, rather than being fast and flashy. In metal that's much more important than "shredding woohoo!!111!". Iced Earth and Kreator are excellent for improving your riffing skills and feel, and they both have vast discographies to choose and learn songs you like.

The path I chose went something along the lines of:

1: Ten Thousand Strong
2:Flag Of Hate
3:Burning Times
4:Phobia
5:Vengeance Is Mine
6:Enemy Of God
7:Travel In Stygian
8:Terrible Certainty(maaaaad downpicking)
9:PUUUUUUUUUUUURE EVIL!!

There's a big jump in difficulty between 5 and 6 but if you master 1-5, 6 and 7 won't be too staggering a challenge. 8 and 9 are insane but also fucking awesome. I say insane because when I say play I mean really getting down the timing, dynamics and precision. Look at how Jon Schaffer plays Burning Times(http://www.youtube.com/watch?v=-oBOuJfXrnU) and any other random bedroom cover of the song, and see how much more confidently and precisely he plays such a simple riff.