My right arrow key is not working, but it doesn't seem to be jammed. Still looks like all the other keys and presses normally... but nothing happens. I have an Acer Aspire laptop. I've tried gently pulling at the key but it doesn't look removable and I'm afraid to break it altogether. Any ideas?
You can pull it quite far. Keyboard buttons are normally clicked in, so I don't see why yours wouldn't be. I've had a similar problem with a Fujitsu Siemens.
What happens when you press really hard?
Since I can't comment I'll go ahead and give an answer.
Yes, some keyboards on laptops just pop off as described. However, several of the newer laptops with the the low profile keys are going to a scissor hinge arrangement which if you force, may or may not cause permanent damage to the key. I don't know whether your model utilizes this style.
To check you can lift up on the edge a key and peer in with some light shined in there. If it is of the scissor hinge type you will see something like this:
This is the style on my Acer Aspire One and my Macbook Pro. The technique to remove these usually includes lifting the key while pushing on the hinge mounting point. This is a demo video on YouTube. While it's for a MBP, the technique is similar.
If it is the old style (which you won't see the hinge) then it's usually safe to just pry them off.
Source: Personal experience...for what that's worth.
First, your keyboard may simply be broken. It does happen, but before you have to consider replacement, you can try these basics to cleaning sticky keys:
Here are two links with additional instructions, which may help you further.