This afternoon we had our first session of D&D 5e with a group we found on the internet.

After finishing our first encounter, I did the following:

• Put me next to the Wizard.


• Cast Guidance on him.


• Send him to check for traps using Perception (he is proficient).


• Cast Guidance on him.


• Send him to check the corpses for items using Investigation (he is also proficient on that).


• Cast Guidance on him.


• Send him to check for what is inside the wooden barrels.

But the DM said that Guidance has a cooldown of a minute per cast (which isn't true), and so it will take me at least 3 minutes.

On the corpses, the Wizard found a rusty scimitar. So I cast Guidance on him in order to let him check the price of the item using Investigation.

The value of the item was 0. So, I asked the DM how will I transmute that with Artisan's Blessing (I'm a Forge Cleric) having 0 value and he said I should do an Arcana check. But I said I'm not proficient and I character is not intelligent (INT -2). He answered that I can't if I am not proficient.

After that, I barely convince him to use Religion instead of Arcana since my channeling ability is from my Gods, and I used Guidance to improve the check. The roll was 3 + 1 = 4, and so the item was useless in any sense.

So my question is: Is allowed a GM to make restrictions on the fly?

Guidance has no cooldown time and as far as I know, an item can't have a literally 0 price. I only choose the forge cleric because I thought I would be able to transmute my metallic enemies items into useful ones!

Is there something I can do at respect? I'm not sure how to handle this situation.

The DM can override the written rules at their table.

D&D 5e has a concept of Rule Zero, which basically means that the DM has final say in any ruling. This means they can impose restrictions outside of the written rules.

Maybe your DM is using a variant ruleset, or maybe they are mixing up the game mechanics with previous editions of D&D, or maybe they simply interpret the written rules differently. It may help to ask why they are using different rules. You may also want to point out the following:

• 
  Guidance has a 1 minute duration, not a 1 minute cooldown. An affected creature can benefit from Guidance once, up to 1 minute after you cast it, although their skill check activity may also take time to perform. See PHB p203:

A spell's duration is the length of time the spell persists.

• Characters may roll skill checks without having proficiency in those skills. See PHB p174:

Without proficiency in the skill, the individual makes a normal ability check.

Regarding the 0gp item: The rules do not specify some minimum price for items. It is reasonable that a rusty chunk of metal would have no market value.

Of course, just because the DM can change the rules, does not mean they should. And it sounds like your DM's overriding of the rules is causing frustration at the table. And that's bad.

You and your DM need to come to an agreement about the rules.

You have a certain understanding of the rules and gameplay, and your DM has a different understanding. The two of you are trying to play different games. Unless this gap is addressed, the disagreements will continue.

For example, your DM asks for many skill checks, possibly to have more difficult non-combat challenges. But you want to use at-will Guidance to make those checks easier, for free. The DM's motives are clashing with yours, causing an antagonistic DM-versus-player situation. Both the player and DM are frustrated as a result.

To handle this situation, you and your DM need to resolve your disagreements about the rules, and expected difficulty, and figure out what game you want to play. First, ask your DM why they are using different rules outside of the written ones that you know. Second, consider scheduling a session zero for the DM and players communicate their expectations for the game. Agree to a mutual understanding of the rules before continuing the game.

The GM's role is to keep the game moving, and make sure everyone is having fun, and following the rules.

Of course, in some situations rules can be bent or broken to allow for certain situations, or in preference of a different approach - i.e. homebrew. If you don't agree with these situations, it might be best to talk to the GM to get an understanding of what they want to achieve.

In regards to your Guidance cantrip casting - this seems like something to discuss between the both of you. From the GM's perspective, casting Guidance consistently might seem like overkill, and if you are always casting it, it raises the minimum DC from 10 to 12. Sure, it's not much, but it changes the flow of the game.

In regards to your situation with the Scimitar - well, it's an old rusty Scimitar. Likely worthless, and if you tried to sell it, even that would take a fairly high Diplomacy check to even try to convince anyone it was worthwhile, and as for transmuting it, well, usually anything to do with magical knowledge is an Arcana check. The Artisan's Blessing does not require any skill checks to complete, but the ritual itself is an hour long, and potentially the GM just wanted to keep the game moving, or they did not see any worth in carrying out the ritual on an old rusty scimitar that was effectively just a piece of scrap.

All that being said, the GM is the one running the game. Their goal is to keep things moving, and make sure that everyone is having fun. And remember - the game is meant to be fun for everyone - that includes the GM.

The DM is free to do anything, but this one was not a good idea

I do not see malice here, just inexperience¹.

There are three possibilities:

1. Misinterpreted the rules


2. Mistakenly thought that Guidance is too strong


3. Actual malice (hates you or your character)

I think it is 2, because of the word "cooldown", it sounds like a homerule to nerf Guidance specifically.

However, it does not need nerfing, it is already balanced. The Cleric's only real out-of-combat utility cantrip provides a small bonus to ability checks, and requires concentration.

Guidance

Duration: Concentration, up to 1 minute. You touch one willing
creature. Once before the spell ends, the target can roll a d4 and add
the number rolled to one ability check of its choice. It can roll the
die before or after making the ability check. The spell then ends.

What you can do

Talk to your DM about this concern.

1. Ask if he gutted Guidance knowingly. I assume yes, but he might still be convinced.


2. If not convinced, ask for this cantrip to be replaced², as it is not the one you picked from the book (that one does not have cooldown).


3. If he still refuses, then there is some malice, and I would look for another group / DM.

1) An experienced DM would not think Guidance is overpowered. One with some experience might think so, but would announce every house-rule before the characters are chosen.

2) Normally cantrips cannot be replaced, but you would not have picked this one if he had announced his house-rule in time.

Technically, whatever the DM says goes, and the rulebooks themselves give the DM the prerogative to overrule any policy he sees fit.

That said, if your DM is directly contradicting the rules then chances are he's either inexperienced, has misunderstood the rules, or is doing something special and making an exception for it.

I would suggest pointing out the contradiction, depending on how well you know your DM. If other players are agreeing with you as well then you have some consensus.

I'd need more information about the social dynamics between your DM, you, and the rest of the group to know more about the best move on your part.

In my opinion:

• The DM is the boss of the game, and his authority should be respected




• The DM also has a duty to know the rules and shouldn't contradict them without a good reason




• The second point above applies doubly so if the DM is wanting to change the rules in the middle of the game. Generally such improvization should be reserved for novel situations.