It is not.
| Task Difficulty | DC |
|---|---|
| Very easy | 5 |
| Easy | 10 |
| Medium | 15 |
| Hard | 20 |
| Very hard | 25 |
| Nearly impossible | 30 |
That depends if I succeed a DC 15 Survival check...
If it is a regular stone and mortar wall with no added difficulties, adventurers are deemed capable enough to climb in 5e - they can climb at half speed (unless they otherwise have a climbing speed) with no roll needed.
Correct, the DM has stakes in mind for success and failure when calling for an ability check in 5e. Some DMs even share those stakes with the player before the roll to reflect that the PC is a capable adventurer at least partly aware of the possible consequences of what they are attempting.
I think there is just some room there in terms of how people interpret 'telegraph'. I think the classical definition would be a sort of less than overt way of communicating something. Telegraphing indicates that there is some indirection, the receiver of the message must make an inference. Now, wet = slippery could be seen as an inference, though its both A) rather obvious, and B) in terms of the real world not an attempt to communicate (wall doesn't talk). Thus not everyone will see it as the GM telegraphing something, though I don't think you are unreasonable to use the term that way.
I disagree, in Gygax D&D Climb Walls was rated as your chance of climbing a SHEER SURFACE, and the common assumption was anything short of that was climbable by anyone, albeit the GM could impose whatever specific obstacles and thus make you describe how you overcame them (or presumably declare the effort impossible, and thus in the realm of the Climb Walls ability).
Yep, pretty much exactly in keeping with early Gygax D&D, PCs are assumed to be super competent, and specific class abilities really mostly only kick in when something would be 'impossible'.
I will grant that different people will have different ideas as to what constitutes telegraphing.
I think we all agree the DM can't possibly describe every possible relevant fact about an environment nor would the players tolerate such monologues. But, if there is something important and possibly dangerous in said environment, I would hope the DM would have that in mind when giving their brief description of the environment in step one of the play loop.
I mean, they could call for a check for 9 out of 10 climbs but, if there are no difficulties involved, why bother? Let the PCs have their movement "victory" and get on to the good stuff. The 5e rules/guidance on Strength ability checks support this.
Old edition rules are old.
Eh, GMs often have a poor handle on what the players are going to fix on. I've GMed thousands of RPG sessions, players still manage to surprise me sometimes. I agree, once someone says they are going in a certain direction, the GM needs to assess exactly what is up. That is true in most systems, certainly 5e.
Oh, I agree, my own system is much more militant on this kind of point, it fundamentally disallows the use of checks unless there are explicit stakes. Of course the GM could also narrate the PC falling on their butt and looking stupid, lol.
Time for a Wandering Grognard Check, what's your luck?Old edition rules are old.
That, and who maintains all these traps in centuries old dungeons? Lifetime warranties on traps would be a bitch to maintain if the lifetime includes liches. 
