Updated - I want to have a detailed post to link to when people ask about the campaign, so I'm putting some more work into this one.
There's been a lot of ambiguity about this, which is incredibly frustrating, but here's how it seems to work.
First of all, the campaign layer seems to work just like in SHIII and 4 - a combination of random and scripted vessels, task forces, convoys and aircraft. You can still go where ever you want - the first thing I did when they let me out of the sub pen was to visit Bergen, which was for some reason patrolled by British vessels, and had a British merchant moored there -- in September 1939. I never knew Norway was a British colony prior to the German invasion
, but I suppose this is something mods can fix easily enough.
The way patrols work, however, is vastly different. In SHIII, if you fired up a campaign set in 1939, you'd be given grid coordinates in the area where the u-boats historically operated, and told to patrol them for 24 hours. In SH5, you're given "missions", which are basically objectives you have to achieve over the course of several patrols. So instead of being told to patrol AA23, then AA13, then AB45, now you've got the option of either sinking 50 000 tonnes in coastal waters or a hundred thousand tonnes in the western approaches. The deadline of these missions is June 1st, 1940.
In the sub pen, you're given the choice of one of these missions - do you think you can best help Germany by hunting coastal vessels along the coast of England, or do you brave the perilous Channel or go around the islands to hunt shipping from the other side of the Atlantic? Different objectives are worth different amounts of points - sinking 50 000 tonnes in coastal waters yield only one point, while sinking twice as many tonnes in the western approaches rewards you with three points. You get to request a new mission each time you leave the pen, so you can hunt in the coastal waters one patrol, then go for a few sorties in the western approaches, then go back to the coastal targets. I just unlocked an objective that tells you to break the British blockade between Britain and Iceland by sinking capital ships that patrol back and forth along a line indicated on the campaign map.
When the campaign ends, it branches into another, based on your performance (at least, that's how I understand it - haven't gotten that far yet).
So basically, as an SH5 skipper you've now got the option of choosing for yourself what area you want to patrol, and you've got more free reins when you do so -- no more do you have to stay within the tight confines of a grid rectangle while fat targets steam merrily past you just a couple miles away. It can be argued that this is not a very realistic approach, but I actually really like what the game is getting at, especially the fact that the AI reportedly reacts strategically to your actions. So I suppose that if I'm very successful at hunting shipping in coastal waters, planes and destroyers will be diverted to this area to protect them, and based on how well or poor you fare overall, the campaign will take a turn for the better or worse over time.
So to summarize:
- There's still the random layer.
- You've no longer got a grid system, but broad objectives to achieve over an extended period of time, such as "sink x tonnes in this area" or "sink ships patrolling along this line".
- According to the game cover, the AI reacts to your every move and shifts strategic power accordingly.
- You now get to change the course of the war, unlike in SHIII where every major event happened according to a script.
My opinion? It's an improvement in some ways, a step back in others.
The briefing you get from your commanding officer:
The in-game campaign map. I've already gotten one point for completing the "Invasion of Poland" tutorial mission.
