Shadow Monk/Assassin Rogue Multiclassing

[ZenBear]

If I want to run a 17 Shadow Monk/3 Assassin Rogue, in what order should I take levels? The character background I'm going for is a Wood Elf raised by Kenku that teach him to be a ninja. Folk Hero for Survival (living in wilderness) and Animal Handling (ride horses, train monkeys to dress like a ninja and lead pursuers away), and the fits the ninja origin of a commoner trained to fight tyranny. Stealth/Perception from class/race. Which class should I start as? When do I dip for Assassinate?

P.S. The monkey thing actually happened. It's part of why people thought ninjas had magic powers. They were thought to be able to shapeshift. Perhaps I'll run a Shadow Monk/Druid some day. 😋

[Dralnu]

Monk 6 / Assassin 3 / Monk+

Monk 6 gets you all the huge things: extra attack, STUNNING STRIKE, shadow leap, spells, good amount of ki. I would not delay this progression.

After 6 the goodies slow, which is a good time to pick up that Assassin 3, then back to Monk.

[DracoKnight]

Monk 6 / Assassin 3 / Monk+

Monk 6 gets you all the huge things: extra attack, STUNNING STRIKE, shadow leap, spells, good amount of ki. I would not delay this progression.

After 6 the goodies slow, which is a good time to pick up that Assassin 3, then back to Monk.

I say go 7 Monk/3 Assassin/10 Monk. This way you get Evasion as quickly as possible. Then after that you can grab the things you want from Rogue. But I would grab Evasion as soon as possible, because you take no damage on a successful Dexterity saving throw, the most common save in the game, which you are also proficient with.

[ZenBear]

Thanks for the responses so far! TBH after reading your suggestions I think Monk 8 first might be best to get that second ASI.

[PoeticDwarf]

Monk 6 / Assassin 3 / Monk+

Monk 6 gets you all the huge things: extra attack, STUNNING STRIKE, shadow leap, spells, good amount of ki. I would not delay this progression.

After 6 the goodies slow, which is a good time to pick up that Assassin 3, then back to Monk.

This sounds as the best idea for me, you don't need more levels monk, maybe monk 7 but 1/2/3 rogue all gives you good things.

[JellyPooga]

I'd be tempted to go Rogue 3/Monk 17, myself.

- You get an extra Skill Proficiency, for a start, from a wider choice of skills, including Deception (to create distractions), Investigation (for finding stuff), Performance (could be a way to infiltrate in plain sight) and Sleight of Hand (always handy for, uh, well, card tricks and stuff?), above those offered to the Monk.

- There's possibly an argument that the Rogues Dex/Int Save Proficiency is a better fit than the Str/Dex of the Monk. Int Saves are generally used to see through deceptions, particularly illusions. Could be a useful thing for a Ninja?

- The abilities you get from Rogue are also mundane, as opposed to the supernatural abilities of the Monk. Just feels like a more natural progression to me, that you first learn the "normal" stuff and then at higher levels learn the "higher mystery" stuff that Monk offers.

Breaking it down by level comparisons:
- Sneak Attack beats Unarmed Strike at earlier levels. At higher levels it's easier to generate Advantage for multiple attacks, but at lower levels, I think a single high-damage attack is probably better than multiple low damage ones.
- Cunning Action trumps Ki. CA has unlimited use and lets you hide as a Bonus Action. Throw Smoke Pellet (Action), Hide (Bonus) and away (Move)! When you do get Ki online, you can use it solely for Flurry.
- Not sure how important to you it is, but getting the Disguise and Poisoners Kit proficiency online quicker seems more thematic to me.
- At 3rd level, the Rogue will also have one of the above mentioned methods of generating Advantage with multiple attacks, through Assassinate. Also; Critical Sneak Attacks end encounters before they start.

[Inevitability]

- There's possibly an argument that the Rogues Dex/Int Save Proficiency is a better fit than the Str/Dex of the Monk. Int Saves are generally used to see through deceptions, particularly illusions. Could be a useful thing for a Ninja?

I believe the default way to see through illusions is an Investigation check. In my opinion, STR/DEX is a better saving throw combo than DEX/INT, at least until psionics start s

Then again, rogue would give you better investigation, so I suppose your argument is still partially correct.