Having finished my first adjacent attacks game, I thought I'd write a little about the game and strategies and how I thought they differed from normal play.
First, a few disclaimers:
1. I played a standard, sequential, flat rate game with adjacent fortifications and no fog on World 2.1. Any other AA games played with different settings are most likely very different.
2. This was my first time ever playing on World 2.1, and so anything that I attribute to AA could actually just be the map.
3. Everything I write, unless it is obviously indisputable fact, is my opinion and may or may not agree with other people's opinions.
I felt the game could be divided up into three parts, which for lack of better terms, I'll call the beginning, middle, and end. Each of these parts had unique events and strategies, and, more importantly, each was affected by AA differently.
I'll define the beginning as the time from the start of the game to the point at which all surviving players had at least one continent and most of their territories were contiguous. This part was probably the least affected by AA, simply because even in a normal game, people tend to only attack one or two territories per turn. Attacking three territories defended by three armies each with a six army deployment essentially amounts to suicide. That being said, as this stage progressed people did begin attacking three and four territories a turn, and probably could have attacked more without AA. I don't think AA changed what happened in this part, but it may have happened more quickly in a normal game.
By my definition, the middle was the time between the end of the beginning and the point at which one player received more armies per turn than all his opponents put together. This stage lasted the longest, and, although the beginning certainly had some effect on the outcome of the game, the winner was ultimately decided in the middle. I think that this was also the part most influenced by AA. Once everyone had a continent, their primary goal became protecting it. The easiest way to do this in AA is with buffer territories. Because your opponents can't attack from a territory they conquer on their turn, as long as you keep at least one buffer territory between your continent and your opponent, it is physically impossible for your opponent to break your bonus.
In many cases, there is one buffer territory between two continents, and the owners of both continents have to fight over it to decide who's bonus remains protected and whose gets broken. I had a lengthy battle with Nooblet over North East Brazil, a buffer territory between his bonuses (Amazonas and La Plata,) and mine (Magreb and Africa as a whole) that was not resolved until the end of the game. Basically, each of us attacked it on our turns, so neither of us got a chance to break the other's bonus.
Sometimes, however there are no buffer territories between two continents, and in these cases the owner of one continent breaks the other person's bonus on his turn, and then the owner of the other continent must use his turn to reclaim his bonus and cannot break his opponent's. This happened to me when I controlled the Middle East and Sully had Indian Subcontinent. He was able to attack Iran, breaking my bonus, every turn, while on my turn I could only take back Iran and could never break his bonus.
The game essentially became a series of stalemated border disputes, in which the front never advanced more than one territory in either direction until the very end.
The main strategy I used was attacking every territory I possibly could every turn and then advancing only one or two armies, so that my opponents couldn't slaughter my entire force. Unfortunately, this eventually led to my loss of the Africa bonus, and then I started advancing all my troops into conquered territories and hoping that sooner or later my opponents would fail to win back the territory and the front would move in the direction I wanted.
I define the end as the period from the end of the middle to the end of the game. In the normal games I've played, the end often begins when one player controls over half the armies on the board, but in this case Sully was the first to manage that, and yet he was not able to kill the rest of us. This was partly due to how slowly AA forced him to advance and partly due to the enormous bonuses in World 2.1. At any rate, AA affected when the end came, but once it did come, the outcome was decided and all AA did was slow it down.
In terms of overall strategy, I think that there is different strategy in normal and AA games, but not necessarily more or less in either one. In AA, there are fewer options during your attack phase, and therefore less strategy involved in picking the best one. On the other hand, there is more strategy involved in the AA deployment phase. If you don't deploy in the right place, you won't be able to fight on all your fronts and your opponent will gain ground that you may never be able to reclaim. As a result the stakes are much higher during deployment in AA than in a regular game.
I hope you had fun reading through all this; I'm not sure how clear I was, but it all made sense in my head