You can't move diagonally past a corner. Does moving through a doorway on the battlemat count as a corner? I.e., I can't move diagonally through a doorway?
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|A1|A2|A3|
|B1|B2|B3|
|==|C2|==|
|D1|D2|D3|
D1 and B1 have a wall between them and D3 and B3. Could I move diagonally from D1 into C2?