What does that even mean??

If I hover my cursor over an abiltiy it will say something like

"Attack/Save: Randged Attack"
or
"Attack/Save: Strength"

Can someone explain this for me please.

So if something says "melee attack" or "ranged attack", it means your character is the one doing the roll, using your attack bonus(either str or dex depending on your weapon, or casting stat in the case of spells that use an attack roll) plus proficiency and any other bonuses against your opponents AC. If it is equal or greater than your opponents AC, the spell or attack hits.

When just a stat is listed, it means the opponent is the one doing the roll, using their bonus in that stat and any other proficiency or bonuses that might apply, against your spell DC, which is 8 plus your proficiency plus your casting stat modifier. If their roll is equal to or greater than your spell DC, they either aren't affected, or depending on the spell they may take half damage or some other effect which is listed in the spell.

Thanks!

Patient ... you have it spot on, but a couple number examples to clarify it if anyone else comes into this thread.

Attack/Save: Attack Roll

Player Attack Roll: Proficiency (2) + Strength or Dex (2) = +4.
Enemy Defense of 16.
The PLAYER makes a roll (1d20+4) to beat this target (16).
So the result has to be 12 or higher on the d20 to hit (12 + 4 = 16)

Attack/Save: Dexterity

Target Dexterity (2) + Proficiency (2) = +4
Spell Save is 8 (base) + Proficiency (2) + Intelligence (3) = 13
So the TARGET makes a roll of (1d20+4) to beat this target (13).
For the target to avoid / reduce the effect, they'd have to roll 9 or higher on the d20 (9 + 4 = 13)


Figured seeing it written out in detail may also help.

You Sir, are a saint, thanks!

This was (and still is) confusing to me.

So you're saying that if a SPELL says "Attack/Save: Ranged Attack" it will use my DEX modifier, and not my INT/WIS/CHA? So ideally, I should be avoiding these spells unless I have a nonstandard stat distribution?

Spells attacks use your casting ability, INT/WIS/CHA.

It should be added: In most cases for spells that has a level:

They generally do full damage on a failed save, and half damage on a passed one. And if the save is failed they usually add some sort of bonus (Like Thunderwave)

This doesn't apply to cantrips like Sacred Flame, which is straight up a "Save or Damage" spell.

Vennumz puts it very well. Just want to add that it's always your class spell ability that is used to determine the DC of your spell. Wizards use Int, Clerics use Wis and Warlocks use Cha.

Further more, there's a difference between a save and an ability check. So spells like Hex that can affect ability checks, doesn't work on Saves.