The reputation system (or Karma as it is sometimes refereed to) is a system used here that allows you to Let a user know what you think of their post without cluttering the forums up with silly posts like
'OO yea!' or
'well said' or
'herehere' or
'm4n 4L1Ve U s0 r0k DuD3!'.
The reputation level of a user viewed by the bars in each of their posts and is based on the amount of reputation points they currently have. Holding your mouse over the bars will display their current standing.
There are 3 different colour of bars:
Green - Positive. The member has a positive level of reputation.
Black - Disabled. The user has disabled their reputation points. In other words - they don't wanna play.
Red - Negative. This member has pissed off enough people that they are in the Red. Usually most members will disable when they get there or are about to go there so they are a rarity.
The number of blips (and the saying that pops up when you hover your mouse over the blips) is relative to how many points they have.
How do I see what my reputation is?
On your User Control Panel homepage, you can view what your current reputation level is and the last 5 remarks that have been left. To get to your UserCP, click Quick Links->
User Control Panel (you must be logged in).
If anyone has given you reputation points, you will see something like:
The first column shows a green, red, or black blip. This represents the type of point adjustment made. Green is positive, Red is negative, and black means that the user did not qualify to leave reputation points (more on that later).
The second column shows the post that the reputation allocation was referring to.
The third column is the date and time it was left.
The last column is for any comments that the user may have left you.
Most users will leave a comment and many will also put their name in the comment (its kind of common courtesy) however this is not a requirement by design.
How do I add/deduct from someones Reputation?
On each post (upper right corner), you will find a button that looks like:

. Clicking that will bring up a window whereby you can choose to 'pat a geek on the back' for making a great post, or let them know you think their post basically sucked.