Rogue Ability Scores

[Expected]

As you have probably noticed by now, I have been theorycrafting various builds and asking for advice on how to improve them. Unfortunately, there are few game shops that host Adventurer's League where I live and I haven't yet been able to find an in-person game (I can't use Roll20 because I don't have a computer, otherwise I would). I am very eager to play and since I haven't been able to, I have a lot of time to prepare.

Anyway, I'm having a difficult time deciding on an ability score array using point buy for a melee High Elf Arcane Trickster Rogue. Originally, I was going to dump Int but I'm not sure anymore, so I'm considering other arrays. I plan to choose Elven Accuracy (+1 Dex) and Resilient (Con). I will wield a dagger/shortsword/rapier (whichever is the first magic weapon I find) and a shield in the offhand. I am going to rely on Sentinel+Mirror Image for offturn Sneak Attacks. I will have Find Familiar (Owl)/Versatile Trickster for advantage. Also, I will be prioritizing Haste for concentration but Blur until I get it. I want to make the best AT possible so I'd appreciate any advice. Please tell me if there is ANYTHING I can do to improve.

These are the arrays after adding racials:
Str-Dex-Con-Int-Wis-Cha
8-17-13-16-12-8
8-17-15-16-8-8
8-17-15-14-12-8

[CTurbo]

I would go with the 3rd one, 8-17-15-14-12-8, because it's easy for AT Rogue's to avoid the Int dependency, and you're likely to want a bit more Con than most Rogues.

[Expected]

Will there be a noticeable difference in spell save DC's successes and failures between 16 Int and 14 Int? Magical Ambush+Hold Person sounds like a fun combo to initiate combat from exploration/RP.

[Rixitichil]

It works out at 5% more likely to save and one less damage on each Booming Blade or similar ability. That difference certainly adds up, but it doesn't make such spells unusable, (or that much worse at all.)
It the same difference as playing a race without an Intelligence increase.

[JackPhoenix]

Where do you get shield proficiency? Rogue doesn't have it, high elf doesn't have it, and there's no mention of Moderately Armored.

[sophontteks]

There is a huge difference between 14 int and 20 int. You'll be noticably worse then spellcasters at save spells. You are looking at a 50% chance for most opponents as your spells are only a DC 10 save. A real caster, by level 4, will have a DC 13 save. A real caster can expect their spells to stick most of the time against most opponents.

So, each ASI is only a 5% chance, but thats actually really significant when you are deciding what is an effecient use of your turn. Its basically like you are using a weapon you are not profecient in until level 9. Casting hold person before level 9 as an opener...alone? Great way to get yourself killed.

At level 9 creatures get disadvantage vs. your saves. They say this is equivilent to -5, but in reality it pushes the spread much closer to the center then a flat reduction would. Its much more likely that a single ASI would make the difference between a success or a failure here.

Which spread is best still depends on your campaign, your team, and the rest of your build. Making an optimized character is about building around the team, so hard to rate this in a vacuum. Overall I think you are using too many feats on a mad class. Resilient, elven accuracy, something for shield prof, sentinal. For the same reasons as spell saves, getting your dex up is also a big deal and its tied to your skills and your AC as well.

[Expected]

Where do you get shield proficiency? Rogue doesn't have it, high elf doesn't have it, and there's no mention of Moderately Armored.

I forgot to mention it, but I'm going to dip into Fighter for one level.

[TheHutz]

I forgot to mention it, but I'm going to dip into Fighter for one level.

Keep in mind you won't be able to cast spells with a Somatic component with a shield in your offhand unless you have the Warcaster feat.

[Expected]

Keep in mind you won't be able to cast spells with a Somatic component with a shield in your offhand unless you have the Warcaster feat.

That's true. Besides Mirror Image and Blur/Haste, I'm not going to be casting during combat, though, so could I theoretically drop my one-handed weapon, cast the spell and then pick it up using my free object interaction?

[TheHutz]

That's true. Besides Mirror Image and Blur/Haste, I'm not going to be casting during combat, though, so could I theoretically drop my one-handed weapon, cast the spell and then pick it up using my free object interaction?

While I think theoretically that could work, since dropping a weapon is a free action, and picking up a weapon is an object interaction, it does completely invalidate one of the perks of the Warcaster feat, so I'm not sure. It may be DM dependent, and others on here may be able to provide more info than my cursory google search turned up.

[Galadhrim]

That's true. Besides Mirror Image and Blur/Haste, I'm not going to be casting during combat, though, so could I theoretically drop my one-handed weapon, cast the spell and then pick it up using my free object interaction?

Typically you will want those spells from the beginning. Your best bet is to just cast whichever one you'll be using, then draw your weapon.

If you are going fighter, why not start fighter for con save, that way you don't need res (con). You also might consider a second level of fighter. Hide-->Hold person (save at disadvantage)-->action surge-->auto crit with booming blade sneak attack