Multiplayer betrayal system - how does it work

Just wondering how the betrayal system works in multiplayer. I’m fairly new to the Halo world and played my first few games of Arena last night. After I died in one of the matches I got the voice over saying “betrayed” and then I got a message pop-up to presumably report or kick the person. I hit the option to do nothing and happily went back to the match. I chose this option based on a few things

  • Not really understanding what the betrayal system was - newb world problem. - The score (I think it was around 25 points each team) - seemed to be a fair game. - The positive chat that was going on - this just seemed like an honest fun match-up. Our team ended up winning the match by 2 or 3 points (still 4v4 at the end) so I felt more than justified in doing nothing.

Does the “betrayed” thing pop-up the first time you kill a team mate or is it after you’ve killed the same person a few times? If it’s the first time and you’ve got newbs like me running around, isn’t this going to affect someones reputation? Up until last night I didn’t know friendly fire existed so may be guilty of blowing up one of my fellow teammates by mistake.

I’ve read a couple of posts that mention people deliberately killing teammates to get their weapon which sounds pretty sad so I’m presuming that’s what the system is aiming to prevent?