diff --git a/src/primaite/config/_package_data/data_manipulation.yaml b/src/primaite/config/_package_data/data_manipulation.yaml
index 6cded5f2..1ec98f39 100644
--- a/src/primaite/config/_package_data/data_manipulation.yaml
+++ b/src/primaite/config/_package_data/data_manipulation.yaml
@@ -740,7 +740,6 @@ agents:
             agent_name: client_2_green_user
 
 
-
     agent_settings:
       flatten_obs: true
 
diff --git a/src/primaite/game/agent/rewards.py b/src/primaite/game/agent/rewards.py
index cabea5f4..7d14e097 100644
--- a/src/primaite/game/agent/rewards.py
+++ b/src/primaite/game/agent/rewards.py
@@ -360,6 +360,38 @@ class SharedReward(AbstractReward):
         return cls(agent_name=agent_name)
 
 
+class ActionPenalty(AbstractReward):
+    """
+    Apply a negative reward when taking any action except DONOTHING.
+
+    Optional Configuration item therefore default value of 0 (?).
+    """
+
+    def __init__(self, agent_name: str, penalty: float = 0):
+        """
+        Initialise the reward.
+
+        Penalty will default to 0, as this is an optional param.
+        """
+        self.agent_name = agent_name
+        self.penalty = penalty
+
+    def calculate(self, state: Dict, last_action_response: "AgentHistoryItem") -> float:
+        """Calculate the penalty to be applied."""
+        if last_action_response.action == "DONOTHING":
+            # No penalty for doing nothing at present
+            return 0
+        else:
+            return -1
+
+    @classmethod
+    def from_config(cls, config: Dict) -> "ActionPenalty":
+        """Build the ActionPenalty object from config."""
+        agent_name = config.get("agent_name")
+        # penalty_value = config.get("ACTION_PENALTY", 0)
+        return cls(agent_name=agent_name)
+
+
 class RewardFunction:
     """Manages the reward function for the agent."""
 
@@ -370,6 +402,7 @@ class RewardFunction:
         "WEBPAGE_UNAVAILABLE_PENALTY": WebpageUnavailablePenalty,
         "GREEN_ADMIN_DATABASE_UNREACHABLE_PENALTY": GreenAdminDatabaseUnreachablePenalty,
         "SHARED_REWARD": SharedReward,
+        "ACTION_PENALTY": ActionPenalty,
     }
     """List of reward class identifiers."""