# Do perception checks to locate Invisible / Hiding creatures auto fail? [duplicate]

The Invisibility condition states:

For the purpose of Hiding, the creature is heavily obscured.

Rules for The Environment state:

A heavily obscured area—such as Darkness, opaque fog, or dense foliage—blocks vision entirely. A creature effectively suffers from the Blinded condition (see Conditions ) when trying to see something in that area.

The Blinded condition states:

A blinded creature can’t see and automatically fails any ability check that requires sight.

A group of 3 characters is under the effects of Great Invisibility and takes the Hide action. Within a minute later, a group of hostile npcs (who do not have any abilities above darkvision and hearing) enters the area. Do they automatically fail all perception checks (thereby granting the invisible party a surprise round)?

## marked as duplicate by Wyrmwood, KorvinStarmast dnd-5e StackExchange.ready(function() { if (StackExchange.options.isMobile) return; $('.dupe-hammer-message-hover:not(.hover-bound)').each(function() { var$hover = $(this).addClass('hover-bound'),$msg = $hover.siblings('.dupe-hammer-message');$hover.hover( function() { $hover.showInfoMessage('', { messageElement:$msg.clone().show(), transient: false, position: { my: 'bottom left', at: 'top center', offsetTop: -7 }, dismissable: false, relativeToBody: true }); }, function() { StackExchange.helpers.removeMessages(); } ); }); }); Mar 22 at 20:57

• – Rykara Mar 22 at 20:17
• Also related: How does invisibility work in combat, though I think different because it deals more with hiding/invisibility once combat has already started. – Rykara Mar 22 at 20:25
• @wyrm I saw that one but think not: This question assumes hiding IS done and asks if that is all that needs to be done without considering aural detection, based solely on the interaction of the rules in the question. – Rykara Mar 22 at 20:38
• It's just reversed. Same question. – Wyrmwood Mar 22 at 20:42
• @rubik I was confused thinking surprise was an optional DMG rule. It's actually a normal rule on PHB 189. – Rykara Mar 23 at 17:58