Hi Mizu, and welcome to the Org . Nice to have yet another Shogun diehard here.

Strange that you can play the battles but not the strategy campaign--I've only been here for a year and a half or so, but I don't think I've seen that particular problem posted here. In order to offer useful advice, we'll need to know more about problem. What kind of PC are you using: general specs like processor speed and amount of RAM, graphics card and amount of video RAM, the Operating System you're using (Windows 98, Millenium, 2000, or XP, etc.) would be helpful. Have you reinstalled the game recently, or are you using an old install?

Regarding the Warlord Edition/Mongol Invasions, my opinion is yes, it is definitely worth getting. You can find it very cheap nowadays, and in addition to the traditional Sengoku Jidai strategy campaign, it offers 3 variants (1530, 1550 and 1580 campaigns in addition to the Mongol Invasion scenario. It also introduced a few new units that you can access, including Naginata cavalry and Battlefield (combat-oriented) ninja. Finally, the AI has been improved in that the Hojo/Uesugi/Shimazu/Mori horde phenomenon doesn't occur as readily towards the end of the game (sometimes "hordes" build up if you take a long time in your conquest, but in my experience, not nearly as fast as in the original game). The cost of most buildings has been halved, as has the time to build most of them.

Provide the information about your computer and try to describe what happens when you attempt to start a strategy campaign. Then perhaps we will be able to offer some useful advice.