So the AI can walk all through my territory and I have to speak to him to threaten war to get him to leave. But when I walk through his territory, he threatens war if I don't leave. That's not parallel. Essentially, when not at war, he has free reign to run my territory while the player does not. I find mid-game, he is running pioneers across the entire map to found a small outpost in the far edge of my territory. In many cases he wouldn't have even known that resource existed as he had not cleared the map yet. The AI shouldn't know about land it has not uncovered yet.
But as your territory is localized and permeable, they can simply walk through and pick off favored spots, turning your lands into Swiss cheese.
I'm not sure why this is standard. I recall the hue and cry around Civ IV before it was patched, and this kind of thing was still allowed. I suppose there's a case that can be made for it being a feature rather than a bug, but it's not a feature I care to embrace.
Seems like the Civ V implementation would be helpful here. Unless you grant Open Borders to another faction, entering that faction's borders automatically triggers war.
I have usually been playing pariden, were it's 50 mana to drop an arcane monolith ahead of a pioneer.
The challenge, for pariden, has been building up enough strength to be effective in the early game (either commanding respect, or to go on the offensive if that's not possible). But pariden is ideally suited for diplomatic victories, in my opinion.
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