The game also sizes bandit parties relative to the player's party size, so if you have 40 troops you'll be more likely to encounter bandit parties of 30-35 troops. This is most noticeable in that there is more food available of more types and it generally gives higher morale boosts than in Mount&Blade.
The game also received a few balance changes. The amount of money that you start with is decided by the host. You can also customize your in-game character with the money that you get from killing other players. For example you could choose from a Swadian Infantry, Swadian Crossbowman, or a Swadian Man-at-Arms. In-game you could choose classes below the maximum upgrade.
Multiplayer for Mount&Blade: Warband includes a lobby with LAN and internet capabilities and rooms with a maximum of 200 players. Unofficial servers have supported as many as 250 players. You can now fight against real players all over the world, on battles of 64 players max on official servers.
The only deviation from this are player made factions, where its vassals will retain the old title of Lord. The vassals of the default kingdoms no longer have the title of Lord, and their titles change depending on the faction they belong to. You can also properly create your own kingdom and rule over vassals as can any other kingdom's leader. The Overland map has been completely rearranged to accommodate the new faction. The expansion includes a new desert-dwelling faction named the Sarranid Sultanate.