A window lock having plural ramped keepers for a window sash and plural rollers movably associated with a slider mountable on a window frame to provide multi-point locking. The ramped keepers are constructed and related to enable delayed lock-up of one roller and ramped keeper relative to the other in order to assure locking of racked or warped windows. A roller and associated ramped keeper are bevelled to counteract any flexibility that might be encountered in a flexible window, such as a window made of vinyl. The actuating mechanism provides for toggle positioning of the rotatable actuating handle and associated drive link to prevent movement of the lock mechanism by outside forces other than the handle. One or more tie bars, each having a roller, can be associated with the slider to provide for variation in the number of locking points and with further variations being achieved by the length of the tie bars as well as the number of rollers mounted thereon.