The general setting:
- I want to play a rogue.
- My party needs me in melee.
- I want to choose the Arcane Trickster archetype.
- XGtE and SCAG are allowed.
I am aware that these basic assumptions conflict with the common consensus about strict optimization of a rogue, so we are talking about optimization under constraints, of course.
The primary objective is to build this character in a such a way that its most important mechanic, the Sneak Attack, can be exploited as efficiently as possible: Maximize sneak damage by enhancing the opportunities to sneak (on- and off-turn) and the probability to actually hit.
The main advantage a melee rogue has over a ranged rogue is that the former is more likely to use the reaction for off-turn Sneak Attacks. This is why my character will be a Human (variant) and take Sentinel as his starting feat. I will also use dual-wielding so that in case of a miss, I can sacrifice my bonus action for a second chance to hit. The main disadvantage of a melee rogue over a ranged rogue is that frontline survivability becomes an issue. This is secondary to my build, though. My current "defense plan" is the following: High dexterity plus Mage Armor give a decent AC, Uncanny Dodge and Evasion provide good defensive abilities, and choosing spells like Mirror Image or Blur will also help. I am open for comments on that and further suggestions anyway, but more in view of combat strategies than abilities.
The general question: In view of my main objective, are there obvious ways to go from there in terms of multiclassing that are demonstrably optimal or at least superior to a singleclass character? This is of course a question of balance: Apart from finding ways which help in using Sneak Attacks, the main difficulty is to determine whether the pay off is worth sacrificing rogue levels (and hence Sneak Attack dice).
Doing three to five levels of Fighter Battlemaster or two to six of Wizard Bladesinger (my DM is okay with relaxing the elf requirement) seem like a good place to look for me. But maybe someone has already done the math and can give a more or less definite answer?
Other things to consider:
- The campaign starts at level 1 and is intended to eventually go all the way up to level 20.
- The rest of the party consists of a Barbarian Dwarf who's going to be our tank and who will usually be right next to me in the frontline (enabling me to use Sneak Attack), a Human Bard focusing on buffs (duh) and fluff, and a Gnome Wizard who likes any spell that incorporates fire (but who will also likely provide me with Mage Armor). Possible strategies that need working together are of course welcome. However, the others probably won't think of their characters as mere assistants to mine. 😉
- The DM plans to provide magic items according to the suggestions in the DMG.
- I am looking more for a dip (no more than around five levels) than for an even multiclass.
- I am not opposed to combining more than two classes, unless the resulting build would heavily violate the above point.