So I have my PS3 hooked up to a Sony Bravia, and on the XMB it's set to 1080p, and displays it to. But when I start up a game ( Assassin's Creed: Brotherhood at the moment, which does support 1080p) it only displays 720p. What's up with that? There are no graphic options within the game or anything.

Check the back of AC:B's box. Does it allow 1080p? A lot of games only go up to 720.

A lot of games are 720p due to the lack of a software upscaler.

 Most retail games only support 720p. The only non-downloadable game I can think of that supports 1080p is Gran Turismo. You're probably wrong about the game supporting 1080p.

Had the same with red dead on the ps3. Only displayed at 720p while other games hit the full 1080. Red dead displayed at 1080p on the 360 *shrugs* No idea why.

You can force 1080p on some games by unchecking 720p on the display settings. However, that results in a decreased performance and whatnot. In the case of older games, it'll downgrade to 480p instead. Regardless, I'd advise just keeping it at 720p; games look better at their native resolution anyway.

" You can force 1080p on some games by unchecking 720p on the display settings. However, that results in a decreased performance and whatnot. In the case of older games, it'll downgrade to 480p instead. Regardless, I'd advise just keeping it at 720p; games look better at their native resolution anyway. "

It says 1080p right on the back of the box. 
"HD Video Output: 480p - 720p- 1080i- 1080p*
 
*Video output in Full HD 1080p requires an HDMI cable and a 1080p native display with an HDMI input supporting HDCP"

"  Most retail games only support 720p. The only non-downloadable game I can think of that supports 1080p is Gran Turismo. You're probably wrong about the game supporting 1080p. "

"It says 1080p right on the back of the box.  "HD Video Output: 480p - 720p- 1080i- 1080p*  *Video output in Full HD 1080p requires an HDMI cable and a 1080p native display with an HDMI input supporting HDCP" "

I bet that they made it able to support 1080p for those with TV's that do not have 720p (since the PS3 does not seem to upscale otherwise). So it is more than likely natively 720p, which is why it goes to that when you boot up the game. Hope this helps!

The resolution of a lot of (small to medium) TVs is actually 1360x768.  So whether the hdmi signal is 720p or 1080p, the output will look a bit crappy either way (because of scaling).

Most games don't support native 1080p.

This just goes to show you that most people don't fully understand HD.

" @Xtrememuffinman: Unless the game is made to be in that resolution, it doesn't happen.  On the 360 it will upscale, but you aren't really playing the game in 1080p only its stretched to fit that.  At this point, 99.5% of games do not support 1080p reso but at the same time I think that 720p works just as well for the games I have seen. "

@Xtrememuffinman:

" @sammo21 said:

" @Xtrememuffinman: Unless the game is made to be in that resolution, it doesn't happen.  On the 360 it will upscale, but you aren't really playing the game in 1080p only its stretched to fit that.  At this point, 99.5% of games do not support 1080p reso but at the same time I think that 720p works just as well for the games I have seen. "

This. 
  

@Xtrememuffinman:

Almost all 360/PS3 games don't support 1080p, they're just being upscaled. You're not missing out playing in 720p, as that's what 99.95% of console games run at. In the case that your TV says it's 1080p in-game, it's simply being upscaled, unless it's one of the very, very few titles that actually support native 1080p. In fact I've yet to see a game with rock hard evidence of native 1080p support. "

Yeah, most PS3 games don't really let you play in 1080P, even though some say 1080P on the back of the box. Some do though, I remember MGS4 did, and oddly enough, I think Blops does (or at least it doesn't pop up a thing saying the TV resolution changed liked how it does in every other case). Probably some other ones, but I can't really think of anything else. 
 
To be honest though, isn't 720P good enough? 

I think most games don't support 1080p, so, while it displays 1080p on the XMB, the game makes it go back to 720p because that's the best it supports. And the native resolution of the TV itself might affect it too. That's the best explanation I've got, anyway.