When contemplating playing again, solo this time and using Vassal, I intended to go with the 2016 rules. The potential of the WBTS game was recognised and we often discussed changes we would make. I was keen to see what changes had been made.
A read of the 2016 rules update and a look at the 2nd Edition map and play aids in Vassal has identified a number of changes, as you’d expect.
In war games, particularly board games, there is the tension between having an historical simulation and a playable game. I always felt SPI tended towards simulation and the updates to the rules by Donald Johnson go towards “improving historicity in many areas.” While this might frustrate some 1st Edition strategies and tactics, it certainly does give you more of the challenges that faced both sides in this war.
At first I thought the map had many changes, but now I think they are more subtle. For instance, a Confederate force besieging Fort Pickens will now be out of supply (however a further change means they can be supplied by water along the coast).
The most exciting change is the inclusion of a railway line linking Florida to Georgia. It starts off out of commission (i.e. it needs to be repaired), but will now be a focus of Confederate endeavours to bring additional ports and supply towns on to the supply grid.
The play aids within Vassal list all the ports, cities and towns and will help in keeping track of ownership and availability. In addition there are supporting documents provided in the Donald Johnson update (the zip file can be found here: http://limeyyankgames.co.uk/resources/war-between-the-states-don-johnson-2015-edition-rules-charts). These include a very handy summary of the rule changes (which helped me better understand them and appreciate them).
Impact of ChangesThe following are my observations on the impact of changes as they affected the game we played. Unless I note otherwise I intend playing with the change in my new game (it looks like I will be playing with nearly all the changes).
Only cities not towns mean retreat results can be ignored. This would have had a significant impact on our game (and stopped the slaughter around Jacksonville).
The South now starts off with lots of forts. This seems significant, but they can easily destroy them and so end up with the 1st Edition’s deployment if they want.
Fort Hatteras now has a function as the North Carolina Outer Banks can be considered land locked with a tidal river now covered by the fort (errata page 5 of the rule book).
The white counters are labels placed by me to note the two land bridges and the "tidal river".
The two forts now cover the approaches to the New Bern seaport
Militia deployment. There are a number that are can be redeployed at setup within their state. This is a great way for the Union to get troops into Cairo from the start. I recall this was a race in the game we played.
Some of the Illinois militia have been deployed in Cairo.
Militia can’t leave their state without a leader [6.15]. There are some significant changes to militia which I will mention later.
Losses caused by force marching can be absorbed by other units in the stack (thereby removing a supply wagon conundrum) and can be reduced by supply expenditure [6.3].
Being entrained across game turns consumes additional railway points [6.53].
Road and rail bridges require both sides to be friendly. Road and rail bridges can be destroyed (and repaired), such activity requires supplies [6.6]. This is interesting as it will slow enemy offensives.
A naval unit can be in a port or fort immune from enemy naval forces, but it is destroyed if the port or fort is captured by enemy infantry. A vessel can retire to fort’s protection if attacked.
Union ironclads (which are distinct from naval flotillas) may sink in an all sea hex [7.13].
Naval transports can move supply points [7.2]. We used to have them carry a supply wagon.
Unopposed Amphibious Assault [7.25]. Basically naval forces will need to be positioned beforehand before assaulting.
Restrictions on Water Transport [7.27]. If you are transported by water you won’t be moving much. I was initially concerned when I first read this, but after confirming my reading was right with the rule's author, I am more relaxed about playing with these restrictions.
All combats are specified before rolling for attack initiative. This would have made a change to our game.
Allocation of losses to combined land and sea forces [8.18]. Naval losses are totalled and then allocated rounding up.
Defender retreating: depot reverts to 2 garrison points, leaving supplies. Naval base is replaced by 1 garrison point and ironclads on last stage of construction are destroyed.
Depot taking loss is replaced by 2 garrison points.
Zones of control. Stacks that have a ZOC are restricted to full corps [9.0]. This is a major change.
Can’t rail or use road into a hex with an enemy fort (as a fort, even besieged, controls the roads and rail network in that hex). Previously could rail or road in and then stop.
Naval zone of interdiction 10MPs in any direction [9.7].
Ironclad SNAFU rule – effective Ironclads do not take losses.
Naval Leaders. Without them have to halt when transiting a fort.
Naval Transit modifiers: +1 if fort on a bluff, -1 fleet has a leader.
Supply consumption can only be not on a supply consumption path for one month [12.1] after that they risk being destroyed. SO, there is no point in storing supplies in a fort for a long siege as they will surrender after two months. Possibly lessens value of siege train. Very major change.
Supply consumption is now fixed [12.12]. Still has the anomaly of 1 factor consuming 25% of the supply a 100 factor stack consumes.
Naval Combat Supply [12.25]. Flotillas need supply to fight.
Siege Combat – siege guns need supply, they can fire at sheltered troops [13.31].
Extended Siege – town/city cut off and enemy combat unit adjacent [13.39].
Attack from March chit at most 1 implies CRT is 0,1 or 2 [14.11]
Infantry ZOC is from a Corps with 3 divisions plus leader [16.21].
Only good commanders of Infantry Corps can command a cavalry unit.
Cavalry ZOC is from a Corp with 2 cavalry divisions plus leader [16.22].
Army HQ may have a ZOC if it meets the same conditions.
Non cavalry commander can command a cavalry corps but at reduced initiative and span.
Cavalry may retreat before combat if not attacked by cavalry. Retreat means leave the hex. [15.22]
Mounted unit can choose to retreat one hex ??? [6.21]
Consumption supply path special cases 
Tracing Water Supply Paths – an empty river transport is not essential provided there is a friendly town/city on the river. So in the North Carolina Outer Banks example, those Confederate forts are in supply, until the Union break into the area.
Must keep track of troops used to form depots.
Rail Repairs need supplies (and rails to be pulled up by the Confederates to be used for their repairs).
Towns/cities captured by Confederates produce supply points that may be collected at the location [12.3], but third paragraph of [21.32] may contradict this??? (Should third “Confederate” be “Union” – this would mean if there was a production supply path, the Confederate gets more than just the monthly supply multiple).
Army HQ deployment requires leader [22.22]
Expenditure of supply for fort and fortress construction is cumulative [22.42]
Change to drafts for the Union to deal with riots and emancipation.
Political Point for enemy HQ destruction.
New and vastly improved Kentucky and Missouri neutrality rules. [25.44 and 25.45].
Also some Confederate cities/towns are sympathetic to the Union and need to be occupied to function for the Confederates.
Optional RulesRetreat after combat may use march attack to try and over run blocking forces
Leader effect on combat die roll
Confederate Initiative Pick
Lee stays East
Grant and Sherman stay West
Special Initiative Restriction. Isolation is determined in the supply phase. If you can not trace a consumption supply path you are isolated .
War is Hell
Random Selection Without Replacement for Ironclad completion, blockade table, siege bombardment, HQ deployment and enemy supply attrition table.
Attacker Wiggle. Basically attacking empty hexes to get a one hex advance. May expend supply, needs to get a retreat result and puts the Generals at risk.
Confederate Rail Construction, but Rome-Blue Mountain line is not shown on map.
The missing Rome to Blue Mountain line
Not using Limited Intelligence as playing solo.
Not using Union Leader Special Rules as Grant and Sherman stay West is enough complication, plus Confederates have Initiative Pick.
Experimental RulesHistorical Leaders – interesting, but will be playing with historical pools (previous game was random).
Leader Loss – will be using.
Political Rules – will use the 2016 rules as they are different to what was used in previous game.
Naval and Fort Combat – will use 2016 rules as they are different to what was used in previous game.