How often is stealth checked?

[Ultrace]

As the title asks, how often is stealth checked? Is it every time the character attempts to move?

Example: If one of my players (a dwarf, moving at 10' round under stealth) is attempting to sneak up from behind on a guard 45' away, are there four opposed checks made before the rogue gets into melee range, or is it just a single check to cover the distance between them? (If something changes, such as the appearance of another character or a change in terrain partway through, that would surely necessitate additional checks, but we're talking two individuals with no change in conditions for this example.)

[King of Vrock]

In general you only need to make a Stealth check when there is someone or thing to oppose that roll. So in your example you're in tactical movement so I would be making checks each move action it takes to close on the guard. So if you're being super careful (assuming 30 ft speed)you're going to need 3 successful checks, but if you take the -5 and move full speed you may only need 2!

--Solid as a Vrock

[StabbittyDoom]

I always use the "once per move action" rule. If they sit still then they don't do another roll. Also, the perception check distance is based on the closest they were at any point in that movement.

[Starglim]

Each time he takes a physical action that might give him away. If he remains still and quiet, he doesn't have to check again.

[erik542]

Here's how I do it: every time the rogues does something noticeable he rerolls. Every time everyone actively looks, they reroll. So frequently the stealth and perception won't be done at same time. Also this is one of the cases where I'd roll for the players behind the screen to minimize the inevitable metagaming.