- Not available on that edition (the reason is in the tooltip)
- Depends on the setting, your class or another addon (details in the tooltip)
What it does
Checks if your current target is within range of the spell you choose, for any spell rather than only your specialization's own. With no target it does not match, and neither does a spell that has no range check against that target.
Why you might use it
Checks whether your current target is within range of a spell, for any spell ID; Spell In Range covers your own specialization's spells. Use it to choose between abilities with different reach, such as a Classic caster falling back to Shoot with a wand, or a Hunter switching to melee abilities when the target is too close for Auto Shot (under NOT). With no target the condition is false. See also Beyond Melee Range and Distance.
Example
Shoot is in range
Settings
What each setting in the condition editor means, from the game's own help.
The icon next to the spell name will automatically update to display the spell that is currently selected. You can drag a new spell from your spell book or action bars into this icon slot to replace your selected spell.
Use this exact spell rank - Unticked (the default), any rank of the spell matches. Ticked, only the rank you chose matches. (only on Classic Era, TBC Anniversary, Forever)
Spell - This is a specific spell used in this condition. You may drag this spell from your spell book or action bars into the input field or spell icon to set this value. This input field has prediction enabled, so you do not have to type the full spell name, just select from the prediction frame when it appears.