The answer is yes.
First, it's important to differentiate the two powers. Friendly Fire is clearly yes, as long as it is within 2 squares of its original target- the target is 1) a creature and 2) within two squares of the target of its original attack.
With Hypnotism, there are two arguments against, as noted in "Can the target of Drunken Monkey attack ...
Horde Breaker must be used on a target adjacent to the one attacked last, not any one that has been attacked during your turn.
The Hunter ranger's Horde Breaker option for the Hunter's Prey feature states:
Once on each of your turns when you make a weapon attack, you can
make another attack with the same weapon against a different creature
that is ...
You can target the ground but the ground will be unharmed
Xanathar's Guide to Everything gives the following optional rule (p. 86)
If you cast a spell on someone or something that can’t be affected by the spell, nothing happens to that target, but if you used a spell slot to cast the spell, the slot is still expended. If the spell normally has no effect ...
No, blade ward can only target the caster
The range of blade ward is "self", and the description says it affects only you:
Until the end of your next turn, you have resistance against bludgeoning, piercing, and slashing damage dealt by weapon attacks.
See the Player's Handbook, page 218.
Only if the DM is absurdly indulgent.
I could see, in some play styles, a player proposing this as a situationally useful trick: we're attacking a sentry who has been on watch in the night for three hours, their eyes are fully adjusted to the dark, and I've got this continual flame spell, maybe it'll blind them for a round and buy us some time. And the DM ...
Yes, but creatures are not thereafter forced to remain hostile
The friends spell can affect any non-hostile creature the caster can 'choose'. When the spell ends, regardless of why it ends, the affected creatures realize, even if it is not true, that you have influenced their mood with magic and, separately, become hostile. Some other spells, like Mind ...
No, it won't blind them
While you can cast it on enemy's helm, it won't do anything besides provide light for those around them.
Nothing in the spell description states the light imparts the Blinded condition. If it did, it would suggest this is possible, but the light just has the brightness of a torch, turning someone's helm into a headlamp won't blind ...
You can't freely touch an object worn by your enemy
The immovable object spell description has no attack roll involved. You always cast it successfully.
This is consistent with other non-combat spells:
You touch a closed door, window, gate, chest, or other
entryway, and it becomes locked for the duration (arcane lock)
A flame, equivalent in ...
Can it target armor or weapons? Yes. Armor: only shields and Leather or Padded. Weapons: All aside from Pikes and Heavy Crossbows.
Does it restrain the wearer? Sometimes, except it doesn't cause the restrained condition.
Is there a save? Yes, for every 10 feet the affected item will be moved. It also takes an action to perform the save.
Not unless you make a Charisma Check against them.
If I cast Friends on myself, targeting the barkeep, but end up in a 2 minute argument with the barbarian and never manage to actually use the spell to try and convince the barkeep to give us a free round she'll be none the wiser. She may notice I've cast a spell, but as long as I don't actually make a ...
Yes you can affect any creature.
tl;dr You can affect any creature, but the spell does not make the other creature aware of the caster nor can it be expected to have much of an impact on a creature the caster doesn't interact with.
Similarity to dream in wording and affecting other distant creatures.
The friends cantrip is worded similarly to dream in ...
Technically, you can use friends on anyone from anywhere
The friends spell has a range of Self and states:
For the duration, you have advantage on all Charisma checks directed at one creature of your choice that isn't hostile toward you. [...]
The description puts no limit or restriction on the "one creature of your choice" besides that that must not be ...
Yup, agreed that this was also how one bypassed Mirror Image(MI) in previous editions, not that this has any bearing on 5e where rules seem to contradict others at every turn for ease of use vs crunch.
Where previous editions of Magic Missile(MM) started with a single dart and ramped up every few levels thereafter, MI images would disappear in a flash from ...
It depends on whether your GM thinks you target somebody when you move hex
In Chapter 10: Spellcasting there is the "A Clear Path to the Target" section, which states:
To target something, you must have a clear path to it, so it can't be behind total cover. [...]
This applies to all instances of a spell targeting somebody - but does moving hex to a new ...