Mystara: The Dark Ages

From the introduction: It is the year one thousand two hundred after crowning. The world has changed, and unfortunately it has changed for the worse. Magic has been so greatly weakened in the last two hundred years that the shackles that held entropy at bay have been unleashed. User summary: This item re-imagines the Mystara campaign setting as a post-apocalyptic, low-magic, low-fantasy setting. While the adaptation was intended for use in D&D 4th Edition, it is generic enough to be used with any version of the rules.