If you don't use immune foes when you were planning on doing so then you are invalidating this players choice, and taking away the agency they showed during character creation.
You will also impact other players who might wonder why you aren't skirting around their weaknesses - or worse, why they bothered to create rounded characters instead of ...
Yes and No. But mostly Yes.
It makes spellcasters worse, by making some spells worse. In particular, the spells you mentioned, i.e., spells that rely on a Duration. Notably, however, other spells are completely unaffected - Eldritch Blast, Fireball, or anything else with Duration: Instantaneous.
Furthermore, not only spellcasters get screwed. The Barbarian ...
Not all scrolls are Spell Scrolls. There is a Scroll of Protection. Granted the list of scrolls that NOT spell scrolls is limited to that one scroll. The section on page 200 is specific to Spell Scrolls.
The effect of the two rules is that anybody that can read a written language can use a Scroll of Protection while you need the spell to be in your class' ...
Remember in D&D RAW, specific overrides general.
The general rule for scrolls "any creature that can understand a written language can read the arcane script on a scroll and attempt to activate it" is overridden by the specific rule for Spell Scrolls: "if the spell is on your class's list you can use an action to read it...otherwise the scroll is ...
You indicated that the player has an interest in picking utility spells when a suitable lightning based spell is not available. I recommend steering the players towards spells whose utility can make a big difference in a fight - there are many useful spells in this category. Also, steer them towards metamagics that can increase their ...
That would be very powerful.
Let's compare the effect with the other things Wish can do:
You grant up to ten creatures you can see immunity to a single spell or other magical effect for 8 hours
You undo a single recent event by forcing a reroll of any roll made within the last round
You grant up to ten creatures that you can see resistance to a damage type ...
Sorcery points are not restricted in which spells they can affect.
Other class features similarly work between classes, as the classes merely grant abilities and few of them state that they have any form of exclusivity. Metamagic abilities and other methods of spending Sorcery Points are not restricted to only affecting Sorcerer spells.
Considering that in ...
The limit is 142 times
Each ritual adds 10 minutes and most spells take 6 seconds1, there are 60 minutes in an hour, 24 hours in a day so 144 lots of 10 minutes, lose just under 15 minutes for the normal casting time so 142 is the maximum. This is likely to be “as many times as the wizard wants” unless his wants are excessive.
Kidding aside; your ...
Taking your hand off the weapon should not require any action expenditure - you are just letting go of it, same as if you dropped it.
You can then use your free object interaction to restore your grip after casting.
The PHB Errata says:
Two-Handed (p. 147). This property
is relevant only when you attack with the
weapon, not when you simply hold it.
About the Rules
You are correct that even if you can do something as much as you want, it still takes time to do. Something that takes your action in combat should not be do-able more frequently than once per 6 seconds outside of combat most of the time (there can be some exceptions, but spellcasting would not usually be considered a candidate for that). So ...
A long rest is interrupted by giving up on it
The text is ambiguous, but 1 hour is meant to apply to the whole period of strenuous activity, while the list is there to define what types of activities could make up that strenuous activity period. The intention is that the rest has to be started over not just for any interruption, but for those unusual times ...
You can end concentration at any time (no action required).
As it says above, you can end it at any time, no action required. It means you don't need to use a reaction, so you can elect to just end it.
Which means yes, you can end your concentration as an enemy approaches so that you drop out of their reach.
The warlock 'upcasts' naturally
Warlocks don't have the options to choose what level of spell slot they use to cast a spell, as other casters do. Their Pact Magic feature assigns a single spell level for all their spell slots, and all their spells are cast at that level.
The Warlock Table lists what level their spells are cast at, which depends on their ...
Yes, you can do this
That's how it goes. Spell slots are regained at the end of a long rest, and there's no rule forbidding spellcasting during a long rest.
It's effective and somewhat cheesy, but not as broken as it might sound at first. To cast that spell before ending the rest, you need to save up a slot for it. If you intend to do this constantly, you ...
Player's Handbook p.203
Once a spell is cast, its effects aren’t limited by its range, unless the spell’s description says otherwise.
From your example, Heat Metal says:
Until the spell ends, you can use a bonus action on each of your
subsequent turns to cause this damage again.
There is no range or LoS limit on this - they can run but they ...
The caster continues casting the spell.
Taking the same quotes from @Xirema's answer, we have the following for casting spells with a long casting time:
Certain spells (including spells cast as rituals) require more time to
cast: minutes or even hours. When you cast a spell with a casting time
longer than a single action or reaction, you must spend ...
Yes. In 5e, prepared spells remain available as long as they're prepared.
From the D&D Basic Rules (e.g. from the cleric's or the wizard's Spellcasting feature):
Casting the spell doesn't remove it from your list of prepared spells.
Basically, 5e Wizards (and Clerics) are 3.5e Sorcerers who can swap out their "known spells" based on their ...
The Dungeon Master's Guide strongly recommends against this.
Dungeon Master's Guide, p.263:
Beware of adding anything to your game that allows a character to concentrate on more than one effect at a time, use more than one reaction or bonus action per round, or attune to more than three magic items at a time. Rules and game elements that override the ...
The Spellcaster would lose the spell
This is relatively straightforward. The rules for spellcasting state unambiguously that a caster casting a spell with a long casting time must use their action each turn to cast it:
Certain spells (including spells cast as rituals) require more time to cast: minutes or even hours. When you cast a spell with a casting ...
Only if the spell says so
There are spells that can direct multiple attacks against the same target, but they use different language. Instead of saying to choose a number of targets, such a spell says that it creates a number of attacks (or strikes, or missiles, etc.) and then requires you to choose a target for each attack. Some spells that use this ...
"1/X Caster" is shorthand for how quickly a character gains "spellcaster levels" (and with them, more spell slots)
The progression for each of these spellcaster types looks like this, with the first column representing Character Level as a Single-classed X and the other columns representing the "Spellcaster Level" they have as ...
Yes, player characters can cast their spells at any time unless something explicitly prevents them from doing so.
Players can cast spells any time they want as long as it's their turn, they have a spell slot available (if the spell needs one; most non-cantrip spells do), and they can provide the verbal, somatic, and/or material requirements.
This does, in ...
You are correct in assuming that the additional action is restricting use of the extra attack class feature. The "one attack only" stipulation is preventing the use of the extra attack feature in the additional action, so a character with extra attack could use his regular action to make 2 attacks and use the additional action granted by haste to attack once ...
Up to you
Quoting from the rules of the Wish spell:
You might be able to achieve something beyond the scope of the above examples. State your wish to the DM as precisely as possible. The DM has great latitude in ruling what occurs in such an instance, the greater the wish, the greater the likelihood that something goes wrong.
However, "casting all my ...
There is no arcana check required for copying from another spellbook.
The rules for copying spells:
When you find a wizard spell of 1st level or higher, you can add it to your spellbook if it is of a spell level you can prepare and if you can spare the time to decipher and copy it.
No check required means no failure is possible. As long as you spend the ...
The act of spellcasting is obvious, but the spell being cast isn't.
The description of verbal components in the rules says:
Most spells require the chanting of mystic words.
And the description of somatic components says:
Spellcasting gestures might include a forceful gesticulation or an intricate set of gestures. If a spell requires a somatic component, ...
You have to concentrate to maintain the spell, and spend your action each turn casting the spell
Longer casting times are noted in the PHB and Basic rules. I'll quote the relevant text from D&D beyond (the official 5e web toolset), since it is the easiest source to search online.
Longer Casting Times
Certain spells (including spells cast as ...
RAW this should be fine
Given that, as you say, the illusion of armour, then the armour being made real, do not 'harm' the enemy, then there's no reason why this would contradict the emboldened part of your quote: "The object can't deal damage or otherwise directly harm anyone".
The fact that the enemy wizard is now unable to cast spells is simply ...
The maximum number of spells a character can cast in a round is 3. You can only take 1 reaction per round, although some monsters have an ability that allows them to ignore this restriction.
You can't cast another spell during the same turn, except for a cantrip with a casting time of 1 action.
This means that you can cast a bonus action spell and a ...
The Basic rules call out two situations where a Concentration check is required to cast a spell: the caster takes damage and...
The spell is Readied but not yet cast (p.72)
The spell has a cast time longer than one action (p.79)
There is no specific rule that I have seen for interrupting spells which can be cast in a single Action, and this seems to be ...