You will always start with a Town Center, a standard number of Villagers and at least 1 scouting unit. You will also start with a Forage bush and near Stone/Gold. The objects that may vary include:
* Scout numbers and/or type: your scout can be your civilization’s standard starting Scout, but it can also be a Serjeant or even a Flaming Camel.
* The second building, if it spawns: all buildings except for Mill, Mining/Lumber Camp, Docks and Caravanserais can spawn.
* Extra resources: far Gold may or may not spawn, while extra resources may spawn scattered across the map.
What is guaranteed is that you will never have a 1 TC, 3-6 Villagers, 1 Scout start.
Regarding the map layout, there's a 30% chance that the map will be land Arabia, a 30% chance that there be oases inside the forests, a 20% chance that the map will be Cenotes-style, a 10% chance that the map will resemble Kawsasan, and a 10% chance that there will be a center lake.
Regicide adds 3 Villagers and a King, while Empire Wars add another 3 Villagers. This map comes in 7 themes: Asian, Autumn, Desert, Grassy, Mediterranean, Tropical and Winter.
Don't confuse this map with wappla's Arabia Random: