While the manual provides some much-needed additional explanation of both Grand Offensives (11.7) and Combat Tactics (21.5), there is still no clear link explained between conducting / planning a Grand Offensive and gaining new combat tactics.
Specifically, the section on Combat Tactics on page 122 refers to "tests" for combat tactics (the text of this entire section is lifted almost verbatim from the LGG board game rules, btw), and says:
"When the test is requested, a D12 is rolled."
In the boardgame tactics research is not tied in any way to conducting a Grand Offensive. It is a totally separate research effort.
The questions are:
1) How do you "request" a test?
2) Is that what a player is doing when you select a tactic on the first turn of a grand offensive? That seems to be the case, but the manual doesn't say that.
3) How do you know if the "test" succeeds or fails? If it succeeds, does that mean you get to use the new tactic in the ongoing grand offensive, or do you have to wait until a later offensive?
4) Has anyone out there succeeded in researching a new tactic? In my last game I did 2 Grand Offensives, selected new combat tactics at the start of each one (heavy bombardment and combat gas) but never got a message indicating what happened, although the new tactics never showed up on the list at the top of the main screen.
Doug