if you lose too much on a ranked playlist in matchmaking you can lose exp
you need to have 100 exp and 10 skill level to become a lieutennant (officer) on halo 3
You win games to earn EXP.
keep doin matchmaking.
Go to Halocharts.com to see
100 exp. and a skill of at least 10
Grifball is a Double EXP Weekend playlist on Halo 3 matchmaking. It resembles football, but with bombs, swords, and Gravity Hammers! Grifball can be played in Halo 3's online multiplayer whenever it is featured as a Double EXP Weekend playlist.
yes if the exp goes under the exp that you needed to go up a grade u will be degraded
yes you can
you go up exp by winning and lose exp by quitting
in HALO 3 you are a Spartan and in HALO 3 ODST you are a Orbital Drop Strike Trooper (ODST)
I expect Bungie to keep the extras from halo 3 and move them to reach. So, to answer your question yes I think they will have double exp. weekend in reach.
You have to get achievements when you playing with a Live account.