Disable device and stealth questions

[Kaboot]

Hi everyone. A few friends and I just started playing this game, and we aren't very good with the rules yet.

I'm playing a rogue character, and I want to get a better grip on the rules that affect me the most.

Disable device; I understand the DC of traps/locks etc. and the 2d4 rounds (for example), what I don't understand is how many DD rolls I have to make.

Do I make one initial roll, and use that result for X amount of rounds? For example, roll a 23 after bonuses, and use that result for X rounds?

Or do I roll at the start of every round, for X amount of rounds? For example, roll 17 first round, 21 second round... until X rounds is over? (X being how long the die said it would take)

Hope that makes sense ha ha

Now the second part

Stealth; When sneaking around, how do I check stealth? Do I roll a stealth check, using some made up DC? Or does my stealth bonus go against the opponents perception? For example, opponents perception minus my stealth bonus?

Any help would be greatly appreciated. Thanks!

[Thurgyn]

From what I understand.

With DD, you make one roll. The more complicated the lock, the longer it takes hence it taking 2d4 rounds. IIRC, each round is 6 seconds so a difficult lock would take 12 to 48 seconds as apposed to 6 seconds or less for a simple one.

With stealth, you roll your stealth check to hide and move silently. Opponents have to roll a perception check equal to or higher than your stealth. Any less and they don't notice you. It does require some form of cover or special ability to do it. You can't really just walk through the middle of an empty room and expect not to be seen. Would be nice if you could though.