信号博弈（Signaling game），是一种由一个发送者（S）和另一个接收者（R）所组成的动态博弈。一开始这个发送者有一个给定的类型（t），接着发送者会观察这个没有其他人（好比说接收者）知道的类型，去从消息堆 M = {m1, m2, m3,..., mj} 中选择送出一个消息（m），接着接收者会观察这个消息后从他可行的动作中 A = {a1, a2, a3,...., ak} 选一个作为反应动作（a），这里要注意的是接收者除了消息之外其他都无法得知（如发送者的类型t），接着根据（t, m, a）的组合来决定双方会获得的报酬或回报。

A signaling game is a dynamic, Bayesian game with two players, the sender (S) and the receiver (R). The sender has a certain type, t, which is given by nature. The sender observes his own type while the receiver does not know the type of the sender. Based on his knowledge of his own type, the sender chooses to send a message from a set of possible messages M = {m₁, m₂, m₃,..., m_j}. The receiver observes the message but not the type of the sender. Then the receiver chooses an action from a set of feasible actions A = {a₁, a₂, a₃,...., a_k}. The two players receive payoffs dependent on the sender's type, the message chosen by the sender and the action chosen by the receiver. A related game in game theory is a screening game where rather than choosing an action based on a signal, the receiver gives the sender proposals based on the type of the sender, which the sender has some control over.