Prussians roflstomp their enemies by virtue of their ideas, sometimes with a 1:2 disadvantage. Therefore, you don't need defensive because you want to handle defense like the dialog says "but attack is the best form of defense."
Probably offensive in lieu of defensive. OP Prussia can run around killing everything anywhere with Offensive and forced march.
Economic is good; however, with Prussia, you *can*, if you choose, take all of the Balkan Coastline as well as everything from Russia around Novgorod and the White Sea. This means you can redirect trade coming in all the way from Asia into the Balkans. Likewise, if you are able to deal with the Emperor or simply become the Emperor yourself, taking Lubeck means never having to worry about money if you pick up trade ideas.
The value in this is that you will need your admin points for coring, and, obviously, your military points are precious if you're going to stay maxed in tech and take multiple military idea groups. Therefore, formulating your strategy around conquests that allow you to turn your diplo points into more money using trade ideas may give you a more balanced approach to stomping all of Europe and making the other players regret ever allowing anyone to play Prussia in the first place.
So, especially in 1.8, the kind of numbers you can get with trade seems to be well above what it was in 1.7, I think in part due to having so many more provinces.
So, I would consider trade ideas if you can take over all the trade power leading to the Balkans and later Lubeck.
You might also consider either humanism or religious. Religious' deus vult which saves you a lot of diplo points when dealing with Catholics, Orthodox and so forth (switching to reformed gives you the largest target list going this route). I personally like humanism when I know I'm going to have a country that can be a big bad blob without it being France, like Prussia. Humanism basically shuts unrest down.
Good luck - make them suffer for their lack of vision.
Good advice for singleplayer, awful advice for multiplayer. I absolutely guarantee you that you'll get very little trade from Lubeck or the Baltic if there's even a semi competent Burgundy, Hansa, Denmark, Sweden or England. Humanism, Religious and Trade are so absolutely worthless in multiplayer for Prussia that you'll be at a huge disadvantage if you take any of those. You don't die to rebels or care much about converting X province a few months earlier when you could be partitioned by your neighbours after a single battle lost. Also, assuming he can take
anything from
anyone in a multiplayer environment is extremely naive.
Military ideas, more military ideas, and military policies. That's all there is to surviving and prospering in multiplayer as a European. Before AoW my "ideal ideas" were Offensive, Innovative, Defensive and Quality in that order, but now due to the new policies with opposite idea groups I believe Offensive, Innovative, Defensive, Economic/Quality is the way to go for the +5% Discipline and +20% infantry combat ability policies. Also go Reformed religion for the +15% morale Führer ability, that when combined with your +20% NI, +15% Defensive idea, +5% DotF and constantly high AT and prestige means you'll have a ridiculous morale advantage over many other players.
Never take an administrative idea group first as a western minor, in my opinion, as you'll need those points for coring the OPM's in the HRE once you're too far over your diplo limit. And with the Imperial integrity there is absolutely no way you cannot fill out a military idea group taken first and still stay up to date with military tech even with a few bad rulers. It's even common to take multiple military idea groups one after a another, you just need to plan for the important techs (tactics, morale, new units) and save accordingly so you're not caught -1 morale down to your neighbour when he attacks you. Also remember to wait for the ahead of time modifier before you take a new tech, just sit on a mil tech until you're about to go to war or are attacked, then you can take the next level.
Getting FM before your neighbours is such a huge advantage in multiplayer as humans are less coordinated than the AI, especially if you're not using voice coms. It's why I love to take Offensive as my first idea group. It's useful in larger player wars where you need to reinforce an ally stack quickly or risk losing a battle and perhaps even the war due to being 3 days late. Defensive is also a must for maintaining 100% AT and further increasing your morale advantage. Never take Quality early, especially as a land nation, it's simply not worth it.
Diplo annex everything you can, you never need to worry about leveling up your diplomatic tech and none of the diplo idea groups are worth it for you. I wouldn't suggest taking Naval or Maritime, while you think it'll help to keep you competitive at sea that's simply not the case. You can build over twice your naval force limit and yet the moment England moves their trade fleet into the baltic you're going to lose
everything no matter what ideas you have taken. Play to your strengths, leave the naval game to England, Venice and whoever else.
Now I noticed the HRE is relatively empty in your game so I highly suggest that you make a pact with Austria and split the HRE in half, he does the leg work early game and you carry him late game. A nice opener for getting ahead early is to day 1 dow the Teutonic Order (Neumark core) and vassalise them in one war, so get an ally to take Danzig and Chelmo then peace out, then you vassalise and the provinces are sold back to the AI vassal. Or just split it with Poland. Be warned however you will be coalitioned by some OPM's so this is where an Austria/Poland/Burgundy ally is useful.
Just my 2 cents as I have lots of experience playing Brandenburg in multiple multiplayer games, and currently involved in one as Brandenburg at the moment.
Here's my Germany in patch 1.4 taking on a 3v7 player war. It was a hell of a war, we preemptively invaded France as to catch the other nations off guard. We blitzkrieged into France wiping as many stacks as possible, and then when the Russians and Polish reached Berlin we regrouped and switched fronts and pushed them back (this is where forced march is absolutely essential), and so on for many years. Don't forget to use scorched earth too, especially if defending, as battles are won by discipline, pips and morale, but wars are won with manpower. We eventually achieved a 60% WS lead before running out of manpower, we were winning the battles but would definitely lose the war if it raged on for another decade, and thus stab hitted for peace. A game with a big Prussia, in my opinion, is much more interesting as they're a great counter to the usual French and Ottoman dominance we see in most MP games, unfortunately they're often killed early on when they're defenceless and vulnerable.
Just survive the early game and have fun wrecking everyone late game.
