Drawing up lists of so-called "Principles of War" have been a past time for strategists for a long time -- since Sun Tzu a couple of millennium ago at least.
Whether it's the pithy Maxims of Napoleon or a whole book-length treatment of the subject like von Clausewitz, coming up with universally applicable principles has proven elusive. A big part of the problem is disentangling the principles of war (which are by definition timeless) from the tactical conditions of the day, especially when those tactical conditions may be very important indeed to the success or failure of a given strategy. Yet the search goes on.
The the extent that wargames accurately reflect the conditions of war, one would expect the principles of war to have some application and I think you do find that they do, but the peculiar conditions of wargames tend to in crease the relative value and importance of some principles while decreasing others.
The principles of war used by the U.S. military currently are objective, offensive, mass, economy of force, maneuver, unity of command, security, surprise and simplicity (as stated in Joint Pub 1 -- Joint Warfare of the US Armed Forces). These principles are not listed in strict order of importance, but they are in rough level of general importance in this list. Every official publication that list these principles or anything similar is always careful to say something like "in all cases, the principles are applied broadly, avoiding literal or dogmatic construction."
That said, I think we can see that some principles seem more obviously and generally applicable across the wargame table than in real life, whereas some important real-life applications of the principles have little relevance to tabletop wargaming.
Objective -- This is one that I think does retain its importance on the wargame table. In a phrase: victory conditions. In real life the challenge is not merely to keep focuses on the objective, but one of the high arts of actual generalship is determining what the objective is. The wargamer has it easier than his real-life counterparts in this regard, because How to Win is explicitly defined, so in this sense the wargamer is more like a subordinate commander in actual operations who is ordered to "Take That Hill" without regard for whether that hill is actually important. Still, one of the easiest and most common mistakes on the wargame table is for a player to lose sight of what the victory conditions are, in the heat of battle, so it does bear in mind keeping this principle in mind -- everything you do should keep in mind the victory conditions.
Offensive -- This principle is of high importance in real-life warfare, but of very doubtful general applicability in wargames. In actual operations it's accepted that final success is dependent on accomplishing some positive goal. A strong defense is to be followed up with an offensive in order to win, for any defense can eventually be overcome. But there are many, many wargames where one side or the other is cast into a defensive role and making an offensive move is not only unwise, but positively dangerous. A well-known example would be the Dunngian wargame Drive on Metz, where it's almost impossible for the Germans to muster the odds to a successful attack and even if they did, it would almost never be a good idea. In wargames where either side can seize the initiative it's still important, but it can't really be considered a principle if it's so situationally dependent. Offensive drops near the bottom of any list of principles of wargaming.
Mass -- Wargaames are, in large measure , all about this principle of war, almost above any other. The forte for wargames is depicting the massing of combat power at the decisive point. So if anything, compared to real life generalship, mass assumes an extra degree of importance in wargames.
Economy of Force -- This is the flip side of Mass, and may be even more emphasized in wargames than it is in real life generalship. The basic idea to to avoid dissipating your strength in secondary efforts in order to achieve Mass. In real life warfare calibrating exactly how much force is just enough is an uncertain business and precision can't be expected. In contrast, it's a big part of good wargame play, especially for traditional hex-and-counter wargames where calculating the exact factors needed for the most effective attacks is vital.
Maneuver -- In actual operations this is generally interpreted to mean trying to gain an advantage in mobility in order to support achieving Mass, and as such is a kind of supporting principle. Proponents of Maneuver Warfare and the Indirect Approach theories that gained popularity in the 20th Century like to emphasis the ability of astute maneuvering to achieve success at less cost in blood and treasure than hard fighting, but all successful maneuver culminates in the application of mass at the decisive point, so I don't see a conflict between these principles. And in wargames Maneuver is inextricably with Mass and Economy of Force as each factor is reflected on the wargame table. Allowing your forces to get pinned down so that they lose the freedom of maneuver can make it hard to achieve Mass elsewhere and obviously violates Economy of Force as well. As wargames are mostly about moving pieces on the board, this has to be considered a principle of elevated importance.
Unity of Command -- This is another critical factor in real life operations, but it has minimal applicability in most wargames. Indeed, even real life battles where Unity of Command was a major issue often see it much reduced in importance in wargames covering the topic. A 2-player Waterloo game is naturally not going to have the same kind of coordination problems (even with a pile of special rules) as Wellington and Blucher experienced. To the extent the Unity of Command issues are introduced in wargames, such as in multiplayer games) the aim is to increase the confusion to reflect reality. Overall, this is definitely the least important principle of wargames and probably even drops off the list.
Security and Surprise -- This pair of principles are really two sides of the same coin. Security is basically guarding against surprise and taking those deception measures you can in order to surprise the enemy. In real life military operations achieving surprise is highly sought after because of the extreme multiplicative effect. In Numbers, Predictions & War Col. T.N. Dupuy's model for predicting combat outcomes suggests surprise can double of triple the combat power of a force. Even in wargames that devote considerable attention to Fog of War such as block wargames and wargames with hidden movement systems the effect of surprise is likely to be much less dramatic. A big reason for this is that the players have much better knowledge of the possible universe of outcomes than real life warriors do. In a wargame it's almost impossible to replicate the kind of complete surprise experienced when something happens that you didn't even consider possible -- or considered and rejected as impossible -- happens. About the only time that experience happens is when you forget a rule -- and no one considers that a positive thing in wargames and players are likely to consider that as ruining the game result when it does. If Surprise plays a small role in wargames, it stand to reason that Security would be diminished as well. Neither principle disappears, but they aren't usually game breakers, although they do play a bigger role in block games and the like.
Simplicity -- The final principle of war on the US military's list, is also a minor principle, largely for the same reasons that minimize Unity of Command. The player is just one mind, or at most one of a handful of minds, controlling the activity of his side's forces and therefore doesn't face all the complications that introducing large numbers of unpredictable human beings into the mix does for real-life commanders. There's still some virtue in simple plans over complicated ones, because the friction of tabletop wargaming is still increased by the number of moving parts, but it's several orders of magnitude less than real-life command and many wargame designs introduce special rules in order to lessen the ability of players to micromanage their armies. Still, the wargamer can plan and execute far more intricate operations with his troops than even the most optimistic commander would attempt with his best-trained, elite veterans.
Bottom line -- If adapted to the wargame table, the principles would need to have their order of importance adjusted to the reality of wargame generalship. I'd suggest the revised order of principles to be as follows -- First Tier (always applicable) : Objective, Mass, Maneuver, Economy of Force; Second Tier (applicable in some games): Surprise, Security, Offensive, Simplicity. Unity of Command is off the list. Thoughts?