D&D 5E Best Magic Initiate spell for a scout Rogue

[Quartz]

Rather than Booming Blade, how about taking Vicious Mockery? You already have a weapon damage attack and you should be getting Sneak Attack damage quite often. But Vicious Mockery is Psychic damage.

 

[ECMO3]

Rather than Booming Blade, how about taking Vicious Mockery? You already have a weapon damage attack and you should be getting Sneak Attack damage quite often. But Vicious Mockery is Psychic damage.

Yeah but with booming blade, I can get the weapon attack, the sneak attack and the cantrip damage all in one attack. At level 5 that is about 4 times as much damage as VM and it does even more if he moves.

 

[ECMO3]

Do you sneak ahead much? Message to tell the party what you find.

For a 1/day spell, look for things with longer duration, so they have a better chance to pay off for you.

This wass definately a thought. When I weighed message vs minor illusion and minor illusion won. Reason why with two familiars in the party, they scout ahead more than I do.

 

[Quartz]

Yeah but with booming blade, I can get the weapon attack, the sneak attack and the cantrip damage all in one attack.

With Booming Blade you just get the weapon's normal effects, not SA damage as well, so for the dagger you only get 1d4 + 3. You don't even get the +1d6 poison damage since that's not a normal effect. (And 1d4 + 3 + 1d6 is hugely powerful at level 3.) Until level 5 you're dropping +2d6 SA and +1d6 poison damage for 1d8 thunder damage if the target moves; at 5th level you'll be dropping +3d6 SA and +1d6 poison for +1d8 thunder and +2d8 thunder damage if the target moves. I don't think it's a good trade-off.

 

[Burnside]

With Booming Blade you just get the weapon's normal effects, not SA damage as well, so for the dagger you only get 1d4 + 3. You don't even get the +1d6 poison damage since that's not a normal effect. (And 1d4 + 3 + 1d6 is hugely powerful at level 3.) Until level 5 you're dropping +2d6 SA and +1d6 poison damage for 1d8 thunder damage if the target moves; at 5th level you'll be dropping +3d6 SA and +1d6 poison for +1d8 thunder and +2d8 thunder damage if the target moves. I don't think it's a good trade-off.

You get the sneak attack damage with both Booming Blade and Green-Flame Blade.

Sage Advice:

Can you use green-flame blade and booming blade with Extra Attack, opportunity attacks, Sneak Attack, and other weapon attack options?

Introduced in the Sword Coast Adventurer’s Guide, the green-flame blade and booming blade spells pose a number of questions, because they each do something unusual: require you to make a melee attack with a weapon as part of the spell’s casting. First, each of these spells involves a normal melee weapon attack, not a spell attack, so you use whatever ability modifier you normally use with the weapon. (A spell tells you if it includes a spell attack, and neither of these spells do.) For example, if you use a longsword with green-flame blade, you use your Strength modifier for the weapon’s attack and damage rolls.

Second, neither green-flame blade nor booming blade works with Extra Attack or any other feature that requires the Attack action. Like other spells, these cantrips require the Cast a Spell action, not the Attack action, and they can’t be used to make an opportunity attack, unless a special feature allows you to do so.

Third, these weapon attacks work with Sneak Attack if they fulfill the normal requirements for that feature. For example, if you have the Sneak Attack feature and cast greenflame blade with a finesse weapon, you can deal Sneak Attack damage to the target of the weapon attack if you have advantage on the attack roll and hit.

 

[Quartz]

You get the sneak attack damage with both Booming Blade and Green-Flame Blade.

I sit corrected.

 

[ECMO3]

With Booming Blade you just get the weapon's normal effects, not SA damage as well, so for the dagger you only get 1d4 + 3. You don't even get the +1d6 poison damage since that's not a normal effect. (And 1d4 + 3 + 1d6 is hugely powerful at level 3.) Until level 5 you're dropping +2d6 SA and +1d6 poison damage for 1d8 thunder damage if the target moves; at 5th level you'll be dropping +3d6 SA and +1d6 poison for +1d8 thunder and +2d8 thunder damage if the target moves. I don't think it's a good trade-off.

1d4+1d6 is not as huge as it seems. It is nominally 1.5 damage higher than using a Rapier, but there is a constitution save against the poison damage and the poison damage is also commonly resisted or immune, so in play it is quite a bit less than 1.5 damage over a Rapier. It is a pretty cool weapon though and thematically is a lot more fun than a Rapier would be.

As for the poison damage with booming blade, I have not thought about that. But I think you would get that too. Here is the text:

"You brandish the weapon used in the spell’s casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack’s normal effects and then becomes sheathed in booming energy until the start of your next turn. If the target willingly moves 5 feet or more before then, the target takes 1d8 thunder damage, and the spell ends."

I think because it says "normal effects" and not "weapon's damage" I think you would get the poison damage too as it is a normal effect of the particular weapon, although I will ask my DM to make sure.