Hello, people of the Internet.

I'm trying to create a build for Jika, my Kobold Artificer. He lives under Waterdeep, worships Gond, has the combined social acumen of Abed Nadir, Sheldon Cooper, and Data, and will eventually build a giant pair of mechanical legs named The Trousers (because he thinks being taller will make kobolds as a species unstoppable). I'd like to level into the Battle Smith specialty, but I'd like to know an ideal build path and maybe even some tactics to make sure he can live long enough to have all his dreams come true.

Any suggestions?

Battlesmiths are a weapon-centric class, which causes problems for species with Sunlight Sensitivity.  Your Pack Tactics lets you partially offset sun blindness, but it limits your options.  Kobold species traits are pretty bad overall, which leaves you in a rough spot.  'Ideal build path' takes more knowledge than any of us have right now, especially since it tends to change as the game progresses, but given how generally bad kobolds are at fighting, I would definitely consider focusing on utility spells and the more supportive end of the artificer.

That said, one curious trick for kobold battlesmiths, specifically, is that if they use their Steel Defender as a mount, Pack Tactics offsets both Sunlight Sensitivity and ranged attack disadvantage when the Defender is in melee range of an enemy.  You and the Defender occupy the same space, which means anything within reach of you is also within reach of the Defender and your Pack Tactics is always on.  As such, a mounted kobold with a crossbow (or gun) fitted with Repeating Shot gains virtually every benefit of Crossbow Expert without needing the feat.  You're limited to non-Heavy weapons (so light crossbows, hand crossbows, and either pistols or muskets if the DM is using the DMG blackpowder guns), but if you work on Sneak Attack rules you can at least contribute during a fracas.  Which is, I assume, what most of the question is fishing for.

Since a mounted Defender operates on the Mounted Combat rules and loses its ability to act independently, you have more room to take the Homunculus Servant.  HS can fly around and also activate your Pack Tactics, as well as providing an "attack" option that doesn't care about your Sunlight Sensitivity.  The homunculus doesn't care how bright it is outside, and since you're riding your Defender and controlling it on your turn, your bonus is freed up to command the homunculus.

You're going to need Mending if you end up deciding to work with both mechanicals, so that's one precious cantrip slot spoken for.  Do not even slightly recommend taking a damage cantrip; you're a battlesmith, you fight with steel and powder, not magic.  Guidance is the other typical must-take, though I find myself not using it as often as I should on my own battlesmith.  You may want to consider another utility cantrip more likely to be useful to your particular campaign.

That would mostly be my start point.  Everything else depends on who else is in your party, what your DM tends to throw at you, and what the goals of both the character and the party are through the campaign.

Quote from Yurei1453 >>

Do not even slightly recommend taking a damage cantrip; you're a battlesmith, you fight with steel and powder, not magic. 

I can't agree with this bit, specifically from the perspective of a small-sized, mounted Battle Smith. As you've mentioned, the Steel Defender goes after your turn, so any time you want to attack after moving (e.g. chasing down a mobile foe, getting out of melee to fire a ranged weapon, getting up close to thwack with a warhammer) you have to use Ready instead of Attack. This prevents you from using Extra Attack as it's no longer your turn, so being able to ready a Green-Flame Blade (or ranged cantrip if that's your thing) is an option I find myself needing quite often, rather than settling for half damage that turn. Yes, Guidance and Mending are probably the most important cantrips for your two artificer picks, but if you take Magic Initiate or have a team-mate who can mend your Steel Defender for you then an attack cantrip is well worth knowing. It also allows us to help with high AC foes that need to die asap if you grab something like Acid Splash / Frostbite / Thunderclap. (the last one also gives you an AoE option, something the Battle Smith is not exactly drowning in)

I very much echo the concerns around picking any Sunlight Sensitivity race as a Battle Smith though. Pretty much everything that I do to enemies needs an attack roll, there's not a whole lot the class can provide that targets saving throws instead that could get around that kobold flaw. You'll be playing a Tesco Value version of a support caster every time it's a warm day outside. If you're dead set on the race then more power to you, but it's also even more reason to take a (saving throw based!) damage cantrip.

Guidance is a bit 'gamey' if that's not your thing, having an automatic 1d4 for all your friends in skill checks out of combat can become more of a chore than a bonus. However, having it as an artificer (someone who likes thinking about situations or strategies and making suggestions on how to improve them) is extremely appropriate flavour-wise. - "Hey, try searching under the carpet / taking a run-up for your jump / scratching the wary dog behind the ears / staying low so the goliath doesn't see you"

One further thing you can do as a mounted artificer that other characters riding medium-sized creatures may struggle with is to make the most out of the Mounted Combatant feat, as you can cast Enlarge on your Steel Defender so that the majority of enemies activate the 'unmounted creature that is smaller than your mount' condition. Nicely, this would negate the downside of your Sunlight Sensitivity even on ranged attacks, making it particularly wonderful for a kobold. I'm guessing that, for your character, making those Wrong Trousers larger would be something they'd want to do anyway.

It's worth noting that when one is using their Defender as a mount, the Mounted Combat rules apply, rather than the Defender's normal "immediately after your turn" rules.  You can have the Defender move during your own turn, but the only actions it can take are Dash, Disengage or Dodge.

While you’re mounted, you have two options. You can either control the mount or allow it to act independently. Intelligent creatures, such as dragons, act independently.

You can control a mount only if it has been trained to accept a rider. Domesticated horses, donkeys, and similar creatures are assumed to have such training. The initiative of a controlled mount changes to match yours when you mount it. It moves as you direct it, and it has only three action options: Dash, Disengage, and Dodge. A controlled mount can move and act even on the turn that you mount it.

So you don't necessarily need to Ready an action to do something on a mounted Defender, so long as you forego the Defender's regular turn and thus its attack.

Good point. Better than forfeiting your Extra Attack, certainly, but I'd still call it an inferior solution to if you had an appropriate attack cantrip available. (Assuming your party's Mending / Guidance needs are still being met in other ways, of course)

Perhaps it's the biased pet owner in me speaking, but my artificer would definitely call her Steel Defender 'intelligent'. (Its INT score is only 1 less than my former paladin) Not autonomous, sure, but we're working on that.

Okay, a few things that haven't been mentioned so far:

1. Insofar as "kobolds are weak": talk to your DM. Have a discussion about sunlight sensitivity in particular. If I have a player who's playing a kobold, I get really lax about my definition of "direct sunlight." After all, if you're in the shade of a building, are you in direct sunlight? I don't think so. If you're in a forest with adequate tree cover, are you in direct sunlight? Not by my definition. I tend to be a little more strict with races like Drow and Svirfneblin, who get advantages to counteract the sunlight sensitivity, but for kobolds... eh.

2. Regarding "how do I live to level 3?": Kobolds and artificers both make kind of crummy direct damage dealers. But what both do really well is support others. In the early game, spells like guidance and faerie fire are clutch support spells, and you can use Grovel, Cower, and Beg with the frontline fighters to really boost their damage potential - especially if there's a rogue in the group. In a bind, hide in shade and cast fire bolt from afar. When you hit two, focus on infusions that help the party - remember, you can hand out infused items, and the party tank will kiss you if you make their armor +1.

3. Once you get to 3, get a hand crossbow, some medium armor, and a shield. Put repeater on the crossbow, and that, plus the shield and some good medium armor, and you should be able to hit 18-20 AC pretty quick. Meanwhile, your defender (I assume your pants?) will be able to deflect any attacks targeted at you, and you can beef up your AC as needed with shield, while providing yourself an extra buffer against damage with heroism. From there, pick up crossbow expert and maximize your Int. Bing, bang, boom.

Thanks, everyone! This is really gonna help. I'm also looking into getting permission from my DM to play an Archanomechanist, which combines Armorer and Battle Smith to create a mecha pilot. We're both fans of giant robots, and he seems cool with the idea, but we're gonna have to see.