Your computer is designed to be used. Still, the more you use it the sooner it will fail. THe drive wears out. The batteries have limited recharge capacity. On the other hand if you put it on a shelf and never turn it on it will also eventually fail as parts like batteries simply degrade with time.
Now how you decide to use it is up to you. Yes, if the CPUs are cranked up a lot it will generate heat. It will probably be reading the drive a lot. It might slow down other use if you are trying to play the game and watch a HD video at the same time.
Ah ok thankyou very much for that, alot of information and has helped me alot! Only thing i wanted to know is if i download the games will it slow down computer all the time? I know that it will slow it down if im running the games but what about if im
Not running the games? Will it slow down the whole comp?
If the games you yearn for work ok on your Mac, the most worrysome issue to deal with is heat. Unless you were playing some ancient text-based game like Zork, any modern graphical game will truly "exercise the hardware" and cause additional heating. So while the Mac is being enjoyed, be sure to get some sort of laptop stand that helps with the cooling. Merely lifting it off the desktop and increasing airflow underneath helps immensely, but there are "gaming stands" that have extra fans to help cool yet more.
As for a slowdown on the general performance of the Mac, just be careful a game doesn't install or run some sort of background process that may cause additional and unseen CPU and/or network load.
Simply downloading the games will not slow down the computer unless as the other poster observers, it starts running something in the background all the time. If you get to the point where you drive is filled to greater than about 85% capacity then it will slow down the computer, but that could be any files, not just games.
Playing games does not quite have the same effect on a computer as driving a car at 100 mph all the time. Yes, in theory it might wear down some components marginally faster, but you would either have to be a really, really heavy gamer for you to notice the difference vs. some component just failing naturally.
The same considerations could apply if you were really into viewing movies 15 hours a day. That's CPU intensive too. Your main enemy on this front is heat so don't game while keeping computer on your lap while wearing your microfleece jammies.
Rereading the thread I notice you mention a 13" MBP. Rather than evilly waiting for you to trip, I'll go ahead and point out that the video infrastructure on those models is not meant for high performance graphics. Besides the fact that graphics output is done using a decidedly not powerful Intel integrated GPU, the RAM where it stores and processes the graphics is shared with the main CPU, something that results in bottlenecks. This is unavoidable, given the architecture. Best you can do to offset the effect is maxing out the RAM as much as your wallet will allow.
Note that MBPs from 2011 on forward can handle a max of 16GB RAM in a 2x8 configuration. In spite of what Apple says.
More info: http://support.apple.com/kb/HT3246
I play or have played the games you mention on a 2010 baseline MacBook Air, which sports a whopping 2 gigs of RAM, a far inferior integrated graphics card to yours, and much less hard drive space (64 gigs). Assuming you have a standard spinning HDD model, the only thing I have that is improved over your unit is my SSD. I play these games just fine on lowest settings and get decent framerates. For the record, I have also installed and successfully played Guild Wars 2 on it.
Naturally, my 2011 15 inch MacBook Pro that I've outfit with an SSD drive and maxxed the RAM blows it out of the water in terms of framerates and higher settings, but the game is certainly playable on the Air. I'm confident that any flavour of Mac built within the last couple of years will have no problem running Blizzard games. How well it runs largely depends on the unit. Obviously, the models with dedicated cards are going to outperform, but the integrated cards are getting really decent these days.
I think gaming is this is the one area Apple has downplayed in its' computer line far too long. They are certainly capable of doing it, and the popularity of gaming has risen substantially. In terms of wrecking your computer... as the first responder says, your computer was designed to be used, and Apple computers are designed for people doing very robust things with their computers, like graphic design, photography and video production. That said, I think it's safe to say that games are no more or less "harsh" on your system than these activities unless you abuse your system intentionally.