The term 'army' in RK Scotland can mean several things, sometimes at the same time.
An Ingame (IG) army is a specific function within the the browser game. It is formed by a level 3 [army way] player of at least one year's playing and a 'two coin noble' (the only function of the game that i have yet discovered which is limited to paying players is leadership of ingame armies, fair enough imho) who needs to have sufficient 'army points' to spend on the various stages of its formation, donated by other [level 3] players. Once enough points are spent, the player may then 'raise a flag'. This is represented by a graphic symbol on the 'groups and armies' screens in the player's location. The next step - recruiting - requires more time and further points, as well as other players.
These other players, leaders of travelling groups which are either brought to or formed in the location of the IG army's formation, may 'merge their platoons' as an action for the day. If they do this their travelling group becomes a 'platoon' within the IG army and sign of it vanishes from the 'groups and armies' screen. Whereas the membership of travelling groups are shown on this screen, that of platoons or the IG army are not.
Upto 7 platoons can be merged into an IG army, each of upto 8 players if led by a lord/noble or 5 if led by a commoner. If an army is merging platoons as its action for the day, notices appear on the groups and armies screen until it has merged platoons either to its maximum number (7) or used up its stock of Army Points.
Once it has platoons, many or all of which might not be at full strength, an IG army can choose to recruit individual soldiers as its action for a day. These soldiers will be posted into the platoons automatically until the platoons run out. An army can only recruit two soldiers per day, so it is much quicker to have an army form out of full platoons than to have to recruit individual soldiers.
Thus, an IG army is composed of a leader, platoons and soldiers. It takes days to raise a flag. It takes days to merge platoons. It takes days or weeks to recruit soldiers to fill out the merged platoons. All of of this requires the expenditure of points, which in turn must be generated by lvl3 supporters who are not the leader. A full army will be the result of the co-ordinated actions of the 56 individual players within it. There will need to be planning in advance and co-ordinated actions every day for extensive periods. It is a collective effort over time.
On top of all this, the IG army leader can hire a sergeant to manage recruitment and a logistics officer to handle supplies.
The soldiers are reliant on either their own individual supplies for food and cash or the army to supply these things. This is because, while in the army, soldiers will need not be able to work, fish, mine, etc for a daily action if they are to remain available for orders to move (of course, if an army is definitely going to be inactive its soldiers can retain their place in its ranks organisationally but do a daily activity as long as it doesn't involve them travelling outside of the location). The less well prepared individual soldiers, or the longer the army remains in the field, the more the soldiers will rely on the army leadership to provide their wherewithal.
6 hours ago