These ideas are probably terrible and I'm more wondering if they are even legal to do. Not that i'm going to but if I really wanted to could I say make some posters saying something Watch Gods of Odds on YouTube or whatever and just post them outside places, so for example like outside schools or public places or is that illegal to do?
I mean sure, it will bring in some more people...but not the kind of people you want. You can also get haters, trolls, bullies, etc. from putting posters up as well. If you want to get the good kind of exposure, participate in gaming conventions and hand out your YouTube channel in the form of a business card to people who you think will be interested in your channel. Of course, talking to them is a must before handing out the card.
Haters gonna hate. Standard...thing is with Youtube...no matter how small you are..we all get hate. 
Well yep very true.Haters gonna hate. Standard...thing is with Youtube...no matter how small you are..we all get hate.
It's completely legal...ish. You just have to make sure if you are posting them on private property that you get permission to do so. A lot of shopping centers, schools, business, etc. have rules against handbills (which is ultimately handing out posters), so you can get in trouble. I don't even know how many people would watch because of the posters. It's probably going to cost you more than it's worth.
Thanks for the reply, Yep I know, I don't actually plan on doing it, I was just curious.
YouTube is your platform, and within YouTube, your videos are your medium. You need to figure things to do with or in your videos that will net the exposure that you desire. The first step in getting the exposure you want is to make content people can actually find. Sorry gaming channels, you're invisible on the YouTube spectrum.
I made this step not too long ago, and it netted the most popular video of my channels history. I started making relevant content, things that people were searching for and that they would find.
Within that, I determined that I would only be able to make the content I would truly enjoy making (while having it be successful) only after I gain a loyal following from trending semi-clickbaity topics.
In short, advertising is not really worth your time, and it would be better for you to spend that time making content people could see.
I made this step not too long ago, and it netted the most popular video of my channels history. I started making relevant content, things that people were searching for and that they would find.
Within that, I determined that I would only be able to make the content I would truly enjoy making (while having it be successful) only after I gain a loyal following from trending semi-clickbaity topics.
In short, advertising is not really worth your time, and it would be better for you to spend that time making content people could see.
I would say it depends from place to place.In some places it MIGHT be banned but i am pretty sure that it isnt exactly illegal however you should be careful where you put up the posters coz TheAimGames said it will attract the wrong audience which isnt something you rerally want for your channel (Obviously XD) and many people (like a school's principal) would consider it as something rude (of course this is only if you havent asked their permission)