D&D 5E Moving Silently While Invisible

[jodyjohnson]

Given the commonality of disadvantage on vision based checks I'd be pretty generous with obscuring noise granting disadvantage on listening checks.

The resolution mechanics for 5e allow 5 states for checks. Auto-fail (no roll allowed), disadvantage, normal DC, advantage, and auto-success (no roll needed) according to the situation.

Generally in a white-room scenario with no visual or audio obscurement invisibility would not automatically grant disadvantage to audio checks. However, with varying levels of noise I would impose disadvantage or even auto-fail depending on distance and ambient noise levels or alternately up the DC or grant a bonus to the Stealth check.

In most combat situations there is a high level of ambient noise making hearing-only perception more difficult.

 

[KarinsDad]

If the foe does not suspect that you are there:

-5 on passive perception vs. Stealth


If the foe does suspect that you are there:

Perception vs. Stealth


If the invisible creature is attempting to sneak through a room full of unsuspecting foes:

-5 on group passive perception vs. Stealth and half or more of the foes have to succeed

The logic behind this is that the more foes are there, the more that they would attribute unexpected sounds to each other. The jingle of armor. That's Fred over there. The creak of a floorboard. Barney shifted position.


If the invisible creature is attempting to sneak through a room full of suspecting foes:

Perception vs. Stealth and any one foe has to succeed



Once invisible, it should be very difficult for anyone to detect a PC (or NPC) without special senses like enhanced smell or tremorsense.

An invisible creature can be detected by sound, or footsteps, or odor, but these are not "discriminatory senses" (term taken from Champions). Sound can easily be lost in background noises, odor can be mistaken or covered up by other odors, etc.

An NPC with a +2 to Perception should not be able to detect an invisible PC with a +2 to Stealth 50% of the time. It should be possible, but not this likely.

 

[Warmaster Horus]

If the foe does not suspect that you are there:

If the invisible creature is attempting to sneak through a room full of suspecting foes:

Perception vs. Stealth and any one foe has to succeed

Agreed, but remember in structured time the use of active perception would require an action (one of a dragon's Legendary actions is doing this) to perform.