Celebrim
Legend
Only in the sense that players are likely to have spells available in every encounter, and not all monsters will. In practice, I find the reverse is true - rules flexibility tends to favor the NPCs for the simple reason that DMs are likely to always be more generous considering their own ideas than they are someone else's "brilliant plans". DM's that are very generous about allowing PC's creative use of spells are also likely at all times to give their magic using NPCs all sorts of 'lair powers' and exemptions from the RAW and in my experience are more likely than not to subjectively remove saving throws from PCs or subjectively give NPCs generous rulings that PCs can't replicate - the NPC's lightning bolt attack is subjectively maximized because the NPC's lair is knee deep in salt water. But the PC's attempts to recreate this situation are ruled to fail, and/or the DM foresees attempts to utilize his own rulings and has NPCs invariably prepared for them. Rules flexibility like this isn't necessarily unfair, 'lair powers' might actually be reasonable and make fights more challenging and interesting in enjoyable ways, but it can be very unfair when the DM is invested in the NPC or in 'winning' and he makes no conscious effort to keep his creativity in check. One of the nice things about consistent rulings and well written rules, it is better allows for the DM to be fair and keep his referee hat even when by personality he invests in his NPCs and is highly competitive and wants to 'win'.
On the contrary, this use of Prestidigitation is actually written into my rules for the spell and works pretty much equally regardless of who uses it - every one adding this color gets a +2 circumstance bonus to intimidate. While I don't normally use intimidate to take away player agency - though I might situational, say a PC is being tortured, where it makes sense to test the character rather than the player and I've failed to think of a great way to test the player (usually because the player themselves plays the PC in pawn stance) an NPC can use intimidate to inflict the shaken status condition on a PC.
In combat perhaps, because one of the big advantages of D&D spell-craft is it generally is fast - requiring but a single round to implement a solution. But by far the player at my table that attempts to wrangle the most advantage out of creativity and who succeeds at it most often, is the player that usually plays skill monkeys. And the reason that this works is that I usually treat creative solutions - even ones using spells - as mechanically of the form, "Pass a skill check to receive a small bonus on success, or waste the action on failure." So while you are correct that some DMs have the habit of just saying "Yes" to spell use and saying "No" to mundane creativity, that's not the only possibility. In my experience though, the tables where that has been true and never consciously considered, are tables where they are most likely to consider their to be extremely poor balance historically between spell-casters and non-casters.
At my table though, I get a lot of, "Can I throw a lasso around the post/skeleton/horse's rider?", or "Can I jump off the building and land on top of the assassin", or "Can I rig up a crossbow so that it fires at whoever opens the door?", or "Can I take the hinges off the door and remove it in one piece?" So when I get things like, "Can I grab the chandelier, swing out over the fight, and attack the X", my responses tend to be more of, "Make a skill check, on success, you can take a +1 circumstance bonus on the attack and gain the Heedless Charge feat for one round. Additionally, I'm going to assume that automatically constitutes an offensive fighting stance. On failure, you are going to waste your action and possibly spectacularly fail." If you have a skill monkey character, this means that you are more likely to have the called for check, and more likely to have lots of ranks in it. Spellcasters aren't as known for their skillfulness, and much of their skill gets tied up in things pertaining to spells and 'knowing' rather than doing. Not that you can't do stunts with concentration, know (arcane), and spellcraft - some are even written into my rules. But if you want to use ray of frost to turn the puddle the berserker is standing in icy or slushy for a round, rendering the berserker 'balancing', causing him to lose his dexterity bonus to AC, and so be available to be sneak attacked by your rogue comrade, I'm more likely to consider this an application of finesse or combat ability than simply knowledge - a trivial attack roll + average sleight of hand check (likely for a wizard attempted untrained) seems appropriate to me here. I'm on the other hand unlikely to say no, since the status inflicted here is small and within what I consider the scope of a cantrip. If on the other hand the player was expecting me to turn the Ray of Frost into effectively the higher level spell Grease, or to just say "Yes" rather than, "Ok, throw the dice", they'd be disappointed.
