Abstract: A toy building brick system includes a brick having an upper wall and an outer wall that is attached to and extends downwardly from the upper wall. The outer wall has a bottom edge that is a free edge. The outer wall bounds a receiving space configured to releasably engage a male connector such that the outer wall and the receiving space defines a female connector. The outer wall has a first notch and a second notch therein each extending upwardly from the free edge and to the upper wall. The first and second notches form grips to facilitate removal of the brick from a male connector.

Abstract: A toy building brick system includes a base brick having a cubic shape such that the base brick comprises six outer walls. The base brick has an open interior and each of the outer walls comprises a female receiver such that six female receivers are formed in the base brick. In this manner, the base brick defines an all-female brick. A plurality of inserts is provided and each of the inserts is removably engaged with one of the female receivers such that an outer surface of each of the inserts faces outwardly of the open interior.

Abstract: A toy building brick system includes a base brick having a cubic shape such that the base brick comprises six outer walls. The base brick has an open interior and each of the outer walls comprises a female receiver such that six female receivers are formed in the base brick. In this manner, the base brick defines an all-female brick. A plurality of inserts is provided and each of the inserts is removably engaged with one of the female receivers such that an outer surface of each of the inserts faces outwardly of the open interior.