The long term objective of this mod is to make the game a little less linear and add enough features to increase its replayability value. So far, there's only a number of NPCs affected but a lot of item related stuff in this mod. Eventually, most of Arx will be affected by this mod.

There are a lot of new features added in Arx Extended but the most important features are:

-Vendors now offer more items, in addition to new ones.
-Some containers like barrels and corpses are more random in contents and quantity.
-There are now more food items to cook like cheese sandwiches, iron rations and filling meals.
-Added more variety of early weapons like iron and steel versions of vanilla melee weapons.
-New bow available for purchase for the "rogue" oriented players.
-New armor pieces and the ability to craft or recycle them.
-Raw materials and junk items can be turned into useful items to be sold or used in crafting.
-Some animals/monsters also drop raw materials when killed like pelts and crafting ingredients.
-Most goblins in their city now use iron weapons and some have unique skins.
-Alchemy has been improved with new ingredients, potions and different mixing methods.
-Some items can stack more like powders, which can stack to up to 20 instead of 10.
-There's a new "sidequest" available in the tavern, indirectly given by Tizzy, the bartender.