CC:E is a card driven game which bears noting in that the mechanic typically doesn't lend itself to true solitaire play. That said, CC:E provides enough variation and open decision making that solo play is not only possible, but can be quite entertaining. Your mileage with these guidelines may vary, but I've found that they create some pretty tense engagements and can put players into tricky decisions.
Setup requires that all objectives be known, though within the appropriate owner's box on the scenario tracking sheet.
2. Force setup
Must be focused on capturing or holding the most valuable grouping of objectives for both sides.
1. Initiative Card Play
There are really two ways to handle this and both work pretty well.
You can play without it completely. This, however, removes one of my favorite play mechanics and I think the initiative card can be a real force balancer.
You can play with it, but use it any time a roll is likely to result in a loss of force. Force preservation is a pretty impartial thing so using it at every opportunity for both sides can be fun. Once it has been used in a single firefight, however, it may not be immediately used by the other side once passed to prevent an endless loop of initiative card play.
2. Agressive Objectives
The biggest thing is that every order or action must be focused on the defense or attack of an objective. This means immediately reinforcing open objectives as defender and working to move toward the high value objectives.
There's plenty of room to play around here, but based on face-to-face play this seems to best simulate a live opponent. Flanking moves are okay, but they still need to be working toward the juiciest objectives first.
3. Time Limit
The game can only extend beyond the sudden death marker by the following formula:
(Total Number of Squads & Teams + Total Number of Leadership Value of leaders on the board) / (Sudden Death Turn/2)
* NOTE: Round up the sudden death turn / 2
The sudden death turn (turn 9) happens and there are 12 squads on the board and 3 leaders with a toal leadership value of 4 (2+1+1) for a total of 16. The sudden death turn was 9 so divided by 2 is 4.5, but we round up to 5.
So, at the start of the sudden death turn we do this calculation and find that this game can go, at maximum, until turn 12.
If the value is less than 1 the game immediately ends.
Play continues and Time! works normally with the possibility of the game ending on a sudden death roll, but the game cannot extend beyond the number of turns calculated.
4. Selecting "Reinforcements"
A number of events can happen where a new unit enters the game as selected on the chart.
Defender - Weapon team with the highest firepower. (This can be ordinance, but should be whichever would be most advantageous at the moment)
Attacker, Recon, etc. - Squad with the highest overall stats.
It just makes things that much simpler and ensures you're always creating a situation that puts the other side at a disadvantage. When in doubt, do what you'd least like to face in the situation and that's the pick.
5. Unit Choices
Any event that requires you to make a choice of units for a negative modifier should be placed on the unit that poses the most immediate threat (are within range) out of the qualifying units, or if none are an immediate threat the one with the highest overall stats (in cases of ties, the one with the highest defensive cover). All things being equal, randomly determine with a dice roll (actual dice).
6. Defensive Modifier Actions
Any time a unit is being fired upon and the base Attack Value is over 10 the target, if in its hand, must play a card with an action to either increase their defense value or reduce the attacker's effectiveness.
Discard your maximum discard every time (Germans and Americans included) if:
a) The attacker and need to move, but don't have a move order.
b) The defender and you have more than 1 broken unit without a recovery order.
c) The defender does not possess a card that modifies the attacker value or defensive value.
Those three rules combined with situations that pop up where you'd normally discard should be observed.
9. Opportunity Fire
The defender must always use opportunity fire if the attacker is moving across open terrain. In this case, attacker and defender may be relative depending on the situation. The attacker stance may be defending an objective from a counter-attack from the defender stance force.
The rule of thumb is:
Whatever hurts or helps the most in the current situation is the correct play.
Sometimes that's not the "smartest" play, but ultimately these solo play guidelines are there to present tactical choices and force an interesting game when there isn't another human making tough choice to try to foil you. It also helps keep the game moving and force combat situations.
I hope that you find the guidelines aren't too strict. Sometimes I forget some of them too, but generally following them has been handy particularly in situations where it wasn't cut and dry what "someone else" would do in a given situation. There is no substitute for a human opponent and VASSAL has a pretty active CC:E community, but hopefully this will help you when you solo CC:E!