All the reinforcement learning algorithms I've read about are usually applied to a single agent that has a fixed number of actions. Are there any reinforcement learning algorithms for making a decision while taking into account a variable number of actions? For example, how would you apply a RL algorithm in a computer game where a player controls N soldiers, and each soldier has a random number of actions based its condition? You can't formulate fixed number of actions for a global decision maker (i.e. "the general") because the available actions are continually changing as soldiers are created and killed. And you can't formulate a fixed number of actions at the soldier level, since the soldier's actions are conditional based on its immediate environment. If a soldier sees no opponents, then it might only be able to walk, whereas if it sees 10 opponents, then it has 10 new possible actions, attacking 1 of the 10 opponents.
What you describe is nothing unusual. Reinforcement learning is a way of finding the value function of a Markov Decision Process. In an MDP, every state has its own set of actions. To proceed with reinforcement learning application, you have to clearly define what the states, actions, and rewards are in your problem.