right now, it is 30 but it increases slightly when you get a dlc
Level 30 is the highest possible level you can get up to without the DLC packs. Each raises the level cap by 5, to a maximum cap of Lv50 with all four installed.
Each DLC pack raises the cap by 5. With Dead Money alone, the cap is therefore 30+5 = Lv35.
to obtain an anti-material rifle in Fallout: New Vegas you have to be at least level 26 for vendors to start selling them at stores.
All four of the DLC area packs (Lonesome Road, Honest Hearts, Old World Blues and Dead Money) raise the cap by 5 each, to a new highest possible of Lv50.
20 but with DLC its 30 i think
They recommend that you be at least level 20.
You get the rebreather in Nellis Air Force Base and you can use it to breathe underwater. You can either gather supplies to make it or with a certain science level you can skip this step entirely.
To become level 31 in Fallout 3, reach level 30 and than use the perk which allows you to level up automatically. This lets you hit 31 and to let you have your stats increase. Note that this isn't a bug and its meant to happen intentionally by the game developers.
With both of the currently released ones, 10. Individually, 5.
http://www.scholastic.com/resources/article/lexile/ The highest possible level is 2000L.
It suggests that you should be Lv25+ to attempt the Lonesome Road DLC but it does not forbid you from entering if you are lower.
Level 30
That is level 15 evil karma.
According to the Hall Of Fame, Pinkstardust has the highest level. There's a possible chance there is someone with a higher level then her though.