I read a thread in the General Discussion forum asking what the requirements are for Main Arena Terrains so I'm going to try to help out with as much of that information as my old brain can remember.
In general here are the "rules" for the LW & MW arenas:
1) Balance
Balance refers to the number and type of bases, and the amount of terrain for each team.
Each team must have equal numbers of small, medium, and large airfields as well as equal numbers of GV bases, ports and CVs.
Terrain balance can be the hardest to attain. When there is a slight imbalance in terrain it can be overcome by modifying the distance between airfields and/or the distance from a base to it's town. Where there is a huge imbalance...start over.
2) Field Locations
There should be no more than one airfield per sector. No more than 25 miles apart. No closer than 3/4 of a sector.
A GV base or port, and an airfield may occupy the same sector.
3) Strat
A complete working strat system must be in place.
This means all factories, roads, trains, and barges must be in place and working.
4) No VOIDs
There should be no "void" object types on the terrain.
5) CVs
Every CV must have a map room associated with it.
Every CV must have a default route assigned to it.
6) No Custom Objects
No matter how much you like that hangar or airfield you made it can't be used in an MA terrain.
7) Airfield Altitudes
No airfield should be over 6k. I use 5k as max airfield altitude.
The simple reason for this is fully loaded Lancasters can't get off the ground above that altitude. They have trouble at 5 and 6k, so anything more just doesn't work.
8) Check Your Work
Use the tools built into the TE to check your terrain. Skuzzy won't fix a hundred errors for you.
Also, fly out of every base. Be sure bombers can take off in at least one direction.
9) Playability
While realistic terrains of Europe look pretty they most likely aren't playable. Take gameplay into consideration when making a terrain.
10) Group Master
Simply put, everything you place on your terrain is a Group Master. The only exceptions to this are Shore Batteries, Spawn Points, CVs, and the map rooms for CVs.
This may be over simplified, but for MA use it's probably the easiest way to put it.
11) Clouds
A complete cloud system is nice but so far as I know not required.
12) Start Over
If you find a glaring problem with your terrain, don't be afraid to start over. You don't know how many terrains I've scrapped 1/2 way through the creation process.
There are probably alot more than my brain can put together right now but with this information people should have a good starting point to make a terrain for the MA.
Remember these are general guidelines. Nothing is etched in stone. Some rules can be bent, but use caution when doing so. As I remember more I'll try to add to this post.
