Random numbers within a processor may be scarce, especially when multiple hardware threads are consuming them. A local random number buffer can be used by an execution core to better manage allocation and consumption of random numbers. The buffer may operate in a number of modes, and allow any hardware thread to use a random number under some conditions. In other conditions, only certain hardware threads may be allowed to consume a random number. The local random number buffer may have a dynamic pool of entries usable by any hardware thread, as well as reserved entries usable by only particular hardware threads. Further, a user-level instruction is disclosed that can be stored in a wait queue in response to a random number being unavailable, rather than having the instruction's request for a random number simply be denied. The random number buffer may also boost performance and reduce latency.