Story Gacha Fgo. On Singularity Campaign debut week, yes, it is worth rolling due to rate ups. Only lancelot and medea lily appeared for my troubles so can't say it wasn't totally worth it, still waiting for a k scope to make Lance useful but heyho These servants are unlocked as one progresses through the main story, and are able to be summoned from the story summon gacha.
FGO (Fate/Grand Order) is visual-novel quality with its story/characters, and easily the strongest of the gacha with a story that I've played. We have channels like gacha rolls where you can share your most likely very lucky rolls, support setups on both JP and NA! and plenty more.. Summon Simulator for Fate/Grand Order with all the NA/Global Summon Banners!
I am saving them up for my Queen, Cleopatra.
For this list we've evaluated more highly those Servants that are useful in the early stages.
So make the most of this opportunity. I used to roll in the Story Gacha when I was young and stupid and didn't know the philosophy behind FGO. The Master had even gone as far as messing with the summoning device.