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+# run-once
+
+This rule warns against the use of `run_once` when the `strategy` is set to
+`free`.
+
+This rule can produce the following messages:
+
+- `run-once[play]`: Play uses `strategy: free`.
+- `run-once[task]`: Using `run_once` may behave differently if the `strategy` is
+  set to `free`.
+
+For more information see the following topics in Ansible documentation:
+
+- [free strategy](https://docs.ansible.com/ansible/latest/collections/ansible/builtin/free_strategy.html#free-strategy)
+- [selecting a strategy](https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_strategies.html#selecting-a-strategy)
+- [run_once(playbook keyword) more info](https://docs.ansible.com/ansible/latest/reference_appendices/playbooks_keywords.html)
+
+!!! warning
+
+    The reason for the existence of this rule is for reminding users that `run_once`
+    is not providing any warranty that the task will run only once.
+    This rule will always trigger regardless of the value configured inside the 'strategy' field. That is because the effective value used at runtime can be different than the value inside the file. For example, ansible command line arguments can alter it.
+
+It is perfectly fine to add `# noqa: run-once[task]` to mark the warning as
+acknowledged and ignored.
+
+## Problematic Code
+
+```yaml
+---
+- name: "Example with run_once"
+  hosts: all
+  strategy: free # <-- avoid use of strategy as free
+  gather_facts: false
+  tasks:
+    - name: Task with run_once
+      ansible.builtin.debug:
+        msg: "Test"
+      run_once: true # <-- avoid use of strategy as free at play level when using run_once at task level
+```
+
+## Correct Code
+
+```yaml
+- name: "Example without run_once"
+  hosts: all
+  gather_facts: false
+  tasks:
+    - name: Task without run_once
+      ansible.builtin.debug:
+        msg: "Test"
+```
+
+```yaml
+- name: "Example of using run_once with strategy other than free"
+  hosts: all
+  strategy: linear
+  # strategy: free # noqa: run-once[play] (if using strategy: free can skip it this way)
+  gather_facts: false
+  tasks: # <-- use noqa to disable rule violations for specific tasks
+    - name: Task with run_once # noqa: run-once[task]
+      ansible.builtin.debug:
+        msg: "Test"
+      run_once: true
+```