The Tactics decks represent strategies for a given turn. Some may provide a bonus when attacking for the entire turn, others when defending. Some may influence allies or have other, perhaps longer-reaching effects on the game. From a design perspective, they accomplish three broad goals: They give the players more flexibility and control, they speed up the game, and they encourage conflict (this is A Storm of Swords, after all).

Tactics

At their most basic level, tactics give players more options for how to accomplish their goals. The Control Westeros tactic is an important tool, given that the ultimate goal of both A Storm of Swords and the A Game of Thrones base game is control of territory, especially cities and strongholds. On a turn when you intend to attack one or more strongholds, this is almost certainly a good play (although not necessarily the BEST play). Given that it also yields a bonus to your bids during the Westeros phase, it can be significant even if you don't launch any attacks. The point is that there are many tactics that give different short-term strategies a boost and allow you to do things that might not be possible without them.

Another key aspect of tactics is to accelerate the game. Manage Troops is one of the most obvious ways that this can happen - the extra movement that it enables can allow you to move troops to the front line incredibly quickly, and is also useful in the early game to grab uncontested territory. This is A Storm of Swords, and the focus is on battle and war. Faster grabbing of neutral territory means earlier conflict over contested territory - quite simple, really. Earlier conflict over contested territory means that more of the game will be what the game is about: war.

Finally, we'll touch on a House-specific tactic. One problem that some wargames can have is that there is insufficient incentive to actually go to war - not an issue in A Storm of Swords. Not only do the starting positions provide some immediate points of conflict, but House-specific tactics such as Ours is the Fury give an even greater incentive to take the fight to the enemy (in this case, House Lannister). Not all of the House-specific tactics follow this exact template, but they all do two things: They focus on the flavor and story goals of that House, and they encourage Houses to fight one another. Remember that Claim is the resource that wins the game, and strongholds such as King's Landing are worth Claim in their own right. The existence of Ours is the Fury makes King's Landing even more important than it would be otherwise.