Dusthana houses (6th, 8th, and 12th) are the three difficult house positions in the Vedic birth chart. The 6th house governs enemies, illness, debts, and service; the 8th governs sudden events, longevity, legacy, the occult, and transformation; the 12th governs loss, isolation, foreign lands, liberation (moksha), and hidden matters. Natural malefics (Saturn, Mars, Rahu, Ketu) in dusthanas can actually become potent in a concept called viparita raja yoga — when a malefic planet rules a dusthana and is placed in another dusthana, it can negate the difficult houses and create unexpected gains.