This 50-hit Elden Ring illusory wall is probably a bug.

pcgamer.com:

«Hidden path ahead,» «secret ahead,» «try attacking,» these are the sorts of cheeky Elden Ring messages that might just drive you up a wall (after you've taken a swing or two at it with your weapon, that is.)

However, not only are there honest-to-god illusory walls that need to be attacked to dispel sprinkled throughout Elden Ring, one industrious user on the Elden Ring subreddit, teristam, uncovered an illusory wall that takes dozens of hits to reveal.

It's located in the mid-to-late game zone, Volcano Manor, in the secret passageways connected to the Manor's side rooms (covered here in our Blasphemous Blade guide.) You already have to get past one standard illusory wall to discover this passageway in the first place. My mind boggles at what possessed teristam to keep at testing this one.

Now, before you commit to 50 swings minimum on every suspicious wall in Elden Ring, I'd caution that every aspect of this one indicates to me that it’s unintentional. Every other illusory wall in Elden Ring makes a distinctive sound when dispelled. This one just kind of clips away without any fanfare. Additionally, it reappears on resting at a Site of Grace unlike other illusory walls.

Elden Ring guide: Conquer the Lands BetweenElden Ring bosses: How to beat themElden Ring map fragments: Reveal the worldElden Ring weapons: Arm yourselfElden Ring armor: The best setsElden Ring Smithing Stone: Upgrade your gearElden Ring Ashes of War: Where to find themElden Ring classes: Which to choose

What's more, it's a mere 15 feet from yet another normal illusory wall leading to an otherwise-inaccessible room with an item in it. The 50-strike wall leads to an easily-accessed merchant and NPC hub you would have already been able to see on your way