Skill

Skill, is awarded to players of Halo 3’s Matchmaking, along with experience points. This can only be obtained on ranked playlists, such as Lone Wolves or Team Slayer.

Gaining Skill
There is no set process to gain skill, but that your skill is akin and relative to other players currently playing Halo 3 in Matchmaking. You do not gain skill unless you become appreciably and significantly better. If you develop a greater headshot ability, your skill level should rise noticeably, unlike with EXP, which only changes if you win a match. Though skill is earned much quicker by winning free for all games, than by playing team games.

Skill Guide

 * 1-10: Lone Wolves - All you have to do is get in the top 3 to get EXP and a skill point. Many people who play this playlist aren't very good at it, so this should be a breeze with moderate skill.
 * 10-20: Lone Wolves/Team Slayer - Lone Wolves, once again. It is quite easy to advance up until about skill 25, where you may be pitted against experts. Team Slayer is also good if you have a group of friends you can play with, though making sure you stay in contact with each other via headsets is the key.
 * 30-40: Lone Wolves, however this requires a greater amount of skill. If not, then play Team Slayer.
 * 40-50: Same as 30-40.

Alternate Method
 * 1-20: Team Slayer - Play Team Slayer by yourself(No Party) until you reach 20 skill. This should be quite easy to achieve.
 * 20-30: Team Slayer - Now you will start to face more skilled players, to easy go through these get a friend with a skill more then 10 less then yours and make sure that they have a bad kill death ratio(Under 1.00) and a win\loss ratio of less then 0.5. This will make the game try to balance out your skills and find players in between. This will leave you play against players with lower skill then you.
 * 30-40: Team Slayer - You can either do this alone like you did for 1-20 or you can get a group of friends. To easily go up in skill get friends with more then 10 skill of you but make sure you can fight the more skilled players. You should go up a skill every game or two depending on your kill\death spread and your points.
 * 40-50: Team Slayer - To get your 50 you will need 3 friends within the 40-50 range and you must be very organized. Each player must have a headset, communication can win or lose a match. Or you can use the method in 20-30 except with Skill 20-30 players. This will match you against players with about Skill 30. (This is complete bullshit!)

Note: If you plan on bringing lower skill players such as skill 20-30 and 40-50 make sure they have a lower kill death ratio and win ration(Both can be view on Bungie.net) Also be sure that they are able to fight the better players. I would suggest that they maintain a -3 to +3 Kill Death Spread to avoid them from leveling up too quickly requiring you to find another low ranked player.

Complications
However, there are complications to getting up the ranks:
 * One is that when you have played a lot of matches, the game will be able to work out what your "win:loss" or "kill:death" ratio is, and if you start to change the percentage, this will help you go up the ladder and ranking scheme, but if it stays the same, it can make this very difficult.
 * The hardest way to rank up is in Squad Battle as it is usually a 50/50 gamble when you enter the pregame lobby.

Skill and Experience
Skill level and experience are measured in the Matchmaking system. Players will be rewarded with experience Rating Points (RP) earned for winning a game in Halo 3 Matchmaking. Progress from recruit to officer is a reward for many wins and another way for games to be evenly matched.

Experience Rating Points and their associated rank status (Sergeant, for example) will give other players an instant feel for how long you’ve been playing and how that compares to your relative skill level in a given playlist. A player with many RPs and a low Matchmaking skill level might be new to that specific matchmaking playlist. Knowing that is the key to knowing an enemy or teammate.