I should give you negative rep for asking that question....LOL.....
Other users read what you say and can give you either Positive rep or Negative rep. These are the numbers you see after or under people's names.
Here is some reading if you want:
MMA News Forums - FAQ
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The Reputation System:
The reputation system is our way of letting the forum police itself. If you find a post helpful or harmful to our community click on the bar graph looking button on the top right of the post and select whether you approve or disapprove the person's post. This will give or take a certain amount of reputation points, which depends on your reputation factor (which increases with you rep, number of posts, and time here).
To see you Rep and who gave it to you go to your User CP and it will list the last 10 reps you have received. A green block means that it is positive rep, red means that it is negative, and white means that the person either has too low of a rep or too few posts for their rep to count.
A Word of Advice
* Asking to be repped will generally get you more negative reps than positive reps. Nobody likes a beggar.
* Making a thread to complain about being Negged will generally result in you losing much more rep
Important Rep levels
*Start: 10 points
*Can post new threads Outside of Noob Jack City: 50 points
*Can access Priveledged forums: 75 points
* Should your reputation go below negative 75 points you will be automatically banned.
Reputation Factor settings (how much you give or take):
*Start: 1 point
*+1 for every year that you have been a member
*+1 for every 5000 posts that you have
*+1 for 500 rep you have
Other Settings:
* You must have 15 posts before your rep will count on others
* You must have at least 5 rep for your rep to count on others
* You can only give out rep to 8 users per day
* You must give 10 different users rep before you can re-rep a user (to prevent abuse of the system)
Circumventing The Reputation System
We have been hearing rumblings about members PMing people about "rep deals" to rep each other back and forth. If you get one of these messages forward it to one of the admins. We do not take kindly to circumventing the reputation system (which is here for a reason) and anyone caught doing so will have their reputation reduced by 25-50%.