This is why the next section of the DMG is called "improvisation".Learning to roll with the punch is vital. Any advice for new DMs which argues against adapting is teaching bad DMing skills.
Metagaming is using out of character knowledge within a game (notice you are still using this knowledge within the framework of the game.)...right? Like knowing that your PC's have a scry spell so you decide your BBEG has taken precautions against a scry spell...like wards and or protective rituals, which can be quantifiably measured...and may even have a way the PC's could still circumvent it.
Lying, well is lying... it's making up a fabrication that has no basis in the rules, your plans or anything else...for all intents and purposes it is altering reality at a whim in the context of the game and a DM.
Page 27 of the DMG:
".., but don't let them short-circuit your whole adventure by using rituals, either. For instance, the Observe Creature ritual requires the caster to be extremely specific when describing the ritual's intended target. If allowing the ritual to succeed would throw a monkey wrench in your plans for the adventure, you'd be within your rights to rule that the ritual failed to locate the intended target because the caster's description wasn't specific enough."
NO - You wouldn't! First of all, what rights? What right does a person (DM or not) have to lie to another person about what they've done. He didn't put this in character terms. He said the player didn't something that didn't conform to the rules for Observe Creature. This is not the case at all. It wasn't the players actions that dictated this outcome - and lying to the player and telling him that it was IMO is extremely rude.
If you don't wany scrying, just make sure the ritual doesn't exist in your world. Pretty simple. But giving players a tool and then saying "Well, you can't use it when it would really be helpful" is stunningly wrong.
Well, first, I was using "lying" in the sense in what you were reacting to, not the broad-brush stroke that might get used later in the discussion; specifically, fudging or shafting a use or result of a player's ability.
And, in the scheme of things, an ad hoc rules-barrier of Ward Ritual or Magic Tidal Forces have the same result whether you planned for it or not- so yes, the difference between Metagaming and Fudging is timing.
That said, I think the advice, in context, is great because Push-The-Button Scry spells are bad Narrativism in the first place. Pathos, sure, but telling the player he can't use his Instant Shortcut isn't an insult, it is a challenge.
Some posters in this thread seem to be operating under the assumption that every piece of advice in the DMG needs to apply in all circumstances.
If a DM does this frequently I agree it would constitute 'sabotage'. But what if the hypothetical scry-proof opponent(s) was an exception?Exactamundo.
I can understand that DMs want to make plots without having to worry about certain sorts of magic. But letting players take spells and abilities expecting to use them and slyly sabotaging them is not cool in my book.
I'm having trouble seeing why it's better to treat this in a binary manner. Either certain divination spells/rituals (and really, this applies to any class ability) don't exist at all in the campaign, or they exist and always function.
Isn't there a middle ground we're excluding?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.