Does your PC ever fail to spot an ambush?
I play him in LFR, so we get automatically surprised.

But whenever there is an option to spot it, he usually succeeds.
Does your PC ever fail to spot an ambush?
Am I missing something here?
Taking 20 never guaranteed success. It had nothing to do with whether or not you could fail. It simply meant that in cases where you could retry as many times as you wanted, you would eventually roll a 20, so it just short-circuited the process and gave you the 20, at the expense of some time used. Frequently, rolling a 20 doesn't mean you'll succeed, and so taking 20 won't help anyway.
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So why does taking 20 not apply to 4e?
Am I missing something here?
Taking 20 never guaranteed success. It had nothing to do with whether or not you could fail. It simply meant that in cases where you could retry as many times as you wanted, you would eventually roll a 20, so it just short-circuited the process and gave you the 20, at the expense of some time used. Frequently, rolling a 20 doesn't mean you'll succeed, and so taking 20 won't help anyway.
The rules were pretty clear that you could only take 20 in a situation where trying 20-30 times was okay. That meant you couldn't do it in any combat situation, or in any situation where you couldn't retry without consequences (e.g. if failing to pick the lock carries the chance that the chest will explode).
A lock which requires a 19-20 to pick by the party rogue is not a trivial challenge. It's a lock which he/she finds difficult to pick but which can eventually be picked with enough time. A lock which requires a 21+ to pick is one which they just can't pick even with enough time on their hands.
So why does taking 20 not apply to 4e?
Take 20 does not exist as an explicit mechanic. 'Assume a 20' is mentioned when searching a room (DMG p.41 - 'Unless the characters are under a time constraint, assume that they're going to roll a 20 eventually and use the best possible Perception check results for the party.)
In 4e most skill checks (pick lock is one of the few exceptions), have explicit penalties or effects on failure, so Take 20 wouldn't be applicable. I guess given how few skill checks can use it, they decided to leave it out.
If they set things up, then you design the encounter to have favorable man-made terrain to make their initial stealth checks with. Start the sneakier guys -behind cover- where Stealth checks don't mean a damn, as they start off unseen anyways.
I'm guesstimating your Cleric is either a level 14 cleric who started with 18 wisdom and took Skill Training/multiclassed to get perception, or is a level 24 cleric.
1) If you want to use stealth against your party, use stealth monsters. Night hag (level 14 Lurker) has a Stealth of +16, which your cleric is still good against, but it isn't auto lose. If it's the level 24 variant, taking 20 means your monster is never seen, period, with +24 to his checks.
2) If it's the former case, then the Cleric spent a feat or two to be perceptive. Instead of changing the rules just so you can continue to ambush the party the old 'cause the dice said so' way, create encounters where you flat out say 'Alright, here's the monsters you see' while having monsters use terrain in a way the Cleric -cannot- see them until the last. This way, the Cleric can feel like a hero for seeing monsters who hide (which is fair, he spent valuable character resources into being able to do so), and players who are NOT the Cleric can actually have a chance of seeing monsters -at all.-
It's not an arms race, this D&D.
It seems people here asuume 'taking 20' means an automatic success. It doesn't and never has. It will always depend on the DC of the task.
What disturbs me is that lockpicking isn't even a trained only skill. Nothing's stopping the Fighter from taking 20 to pick a lock
That's what I thought. My condolences!I play him in LFR, so we get automatically surprised.![]()
Well, i'd say that Failure to pick a lock means you can possibly BREAK a lock, so it's a consequence of failure, which means you can't take 20 in the first place. I don't know if the skill description has anything like that per RAW, but that's how i'd do it.