Shibou Yuugi de Meshi wo Kuu.

Yuuki wakes up to find herself wearing a maid's uniform in a strange manor. After wandering into the dining room, she comes across five other girls, each in the exact same outfit. Soon, the girls learn that the manor is brimming with lethal weapons and an array of deadly traps…and that they can only escape by playing the most gruesome of games. As the terrifying truth sets in, each girl's face goes pale—except Yuuki's. Why? Because this isn't her first go-round. That's right—Yuuki is a professional death game player who lives off the prize money she collects from winning brutal killing competitions, and she's not about to let this chance pass her by. (Source: Yen Press)