Granitecosmos
2021-02-14, 05:59 PM
Goals and Priorities
This build attempts to achieve two things.
Be able to grapple gargantuan creatures.
Achieve this without transformation, using Rune Knight's Giant's Might.
This will be a pure grapple/shove build; damage is not the focus, enabling the rest of the party is. The general priority:
Reaching peak grappling potential. Advantage, size buff, general roll manipulation and Athletics bonuses.
AC, saves, damage resistance, hit points. You can't do your job when you're dead.
Party utility. Anything that isn't direct damage but doesn't only benefit you specifically to do your job.
Damage. It's not the focus of the build, therefore it's last on the list.
Colour Code:
Gold: Icredible stuff.
Sky Blue: Great feature.
Blue: Useful option.
Black: Meh. Not good, not bad.
Red: It's a trap or just straight-out bad.
Green: Situational.
Point Buy Array
15, 14, 13, 12, 10, 8 is our go-to choice. 15, 14 can become 16, 16 with a +2/+1 race; those two will be STR and CON, respectively. The 13 lets us multiclass into either Bard or Rogue for Expertise and Enlarge. A +2/0 race would drop the 15 to a second 14, sacrificing a CON bonus to put the points elsewhere. INT is the preferred dump stat, if you're not going to multiclass into CHA classes feel free to drop that to 8 as well. The build itself is rather MAD not strictly due to multiclass but because we really want high initiative, CON and WIS saves on top of ideally 20 STR.
That being said, if you'll absolutely pick up War Caster at one point it's not a terrible idea to drop CON to 14, even with a +2/+1 race; the extra points can bump WIS to 13 (which will become 14 later on), as well as DEX to 12 (or 14 if you dumped CHA as well); alternatively CHA 14 instead of DEX 12 if you want two Bardic Inspiration dice. This will leave one point that you can put anywhere since it'll be utterly inconsequential. You trade a +1 CON bonus and up to 20 hit points total for +1 WIS and +1 DEX/CHA bonuses; buffing your weaker saves and/or adding utility, the trade-off is valid and will come down to personal preference.
Race Choices
I'm not going to mention stuff like Water Genasi drowning creatures with grappling underwater or Aarakocra dropping creatures for damage. This is a party enabler build, damage and kill speed are not your concerns, you have the rest of your party for that. Small races can still reach the coveted huge size; Giant's Might upgrades size to large instead of just increasing the size category. Small races will rely on Giant's Might much more than medium ones; this does mean they are better suited for the Rogue route since Enlarge doesn't let them save Giant's Might uses for later, thus it doesn't hurt as much if Enlarge acquisition is delayed. Let's dive in:
Bugbear. +2/+1, Darkvision and Powerful Build; latter only for DMs who insist on push/drag/lift weight rules for moving grappled creatures. The reach is useless for grappling, unfortunately; its duration is strictly between the beginning and the end of the attack itself, which means grapple breaks the moment you conclude the grapple contest, regardless of outcome, if the target wasn't within 5ft. Still useful for shoving but its utility is very limited overall.
Centaur. +2/+1, 40ft speed, 1d4 unarmed and Equine Build which is Powerful Build with a situational mobility penalty you can ignore 99% of the time during your grappling shenanigans. One ruling insurance and two luxury features make this blue. This one becomes sky blue if your DM allows jumping shenanigans; read more about that further below, in the Bard path section about Longstrider.
Custom Lineage. +2/0, Darkvision and an early feat. I'd rather pick a +2/+1 race but there's one specific circumstance where I wouldn't even think before picking this: when the majority of my party is using ranged attacks and/or DEX-save based abilities. The extra feat lets you pick up Grappler at first level, or alternatively Shield Master for the shove which you can use to widen the gap between friends and foes instead of shoving prone. Point in case, the extra feat lets you grab Grappler without losing out on other, generally better feats.
Duergar. +2/+1, Superior Darkvision, Duergar Resilience, once-per-day Enlarge at level 3 which is mostly overkill but still very nice, once-per-day Invisibility at level 5 for utility and the weapon proficiencies can be traded in for even more tool proficiencies to turn you into a swiss army knife. Even better, you couldn't care less about Sunlight Sensitivity; grapples and shoves are not attack rolls and you have your party for Perception checks. The Alert feat can negate the one true danger of perception disadvantage anyway. The 25ft speed stings a bit but for this package it's a perfectly acceptable trade-off. Still not sold? +1 STR and +2 CON means you don't really care whether the DM allows Tasha's optional custom origin rule (but if they don't, you can't do the 14 CON trade-off), the array will work for you regardless.
Gnome, deep. +2/+1, Superior Darkvision and Gnome Cunning makes this small race a fine choice if you're looking for this combination specifically. If you're fine with standard Darkvision, Yuan-Ti Pureblood is simply better in every way; that being said, if Yuan-Ti Pureblood is banned at the table (it likely is), this is your go-to choice for WIS save advantage and consider it sky blue.
Goliath. +2/+1, cold resistance, Powerful Build and Stone's Endurance. Latter is especially powerful during lower levels, it's essentially an extra HD you can roll during combat throughout the game. What really sells this ability is the damage decrease directly translates into a lower concentration save as well, at least once things start hitting hard, and is applied after resistances! +2 STR and +1 CON means this race can also perform well if Tasha's optional rule isn't allowed.
Halfling, lotusden. +2/+1. Lucky, Brave and Spike Growth; the first two are nice features that can help with saves as well, latter is the only way you can pick up Spike Growth in this build. Damage is not a priority but this grants you the option to lay down some serious hurt; Giant's Might leaves your concentration slot for other things, this is a fine candidate. You can drag grappled creatures back and forth through Spike Growth to deal 4d4 damage every turn with just your movement alone. Longstrider will increase this by 2d4, Mobile grants another 2d4 on top of that. You can dash to double that total for up to 16d4. If you can dash as a bonus action and as an action at once, you can do up to 24d4 damage per turn. That's 60 magical piercing damage on average; no save, no attack roll, deal with it. Of course, you still have to grapple the victim first. Once per day but still nice; a Druid or Ranger can also cast this for you, turning this into blue if that's an option, sky blue if it's not.
Kobold. +2/0. This is a potential trap new players might fall into: ability checks are not attack rolls, making Pack Tactics useless!
Half-Orc. +2/+1; honestly on the list only because +2 STR and +1 CON means you don't rely on Tasha's optional rule. Darkvision and Relentless Endurance aren't useless but just aren't enough to make this race compete with the rest.
Hobgoblin. +2/+1, Darkvision and Saving Face, which is a once-per-short-rest die manipulation of up to +5 bonus on essentially any d20 roll of yours that you would otherwise fail, including even death saves. This alone is a worthwhile investment as you can hold this for crucial saves or other rolls. A nice DM will let you know whether you can use this to change the outcome before you commit, otherwise it's still a gamble. Hire some mercenaries, commoners or get sidekicks to max the bonus if your total party size is lower than 6. Pets, familiars and animal companions also count, as long as they aren't invisible. The armor and weapon proficiencies can be turned into tool proficiencies for utility.
Loxodon. +2/+1, Powerful Build and an extra appendage you can grapple with. If you want to grapple more than one creature at once and you want to use a shield as well (you really should), this is your best option. If you want to go the Rogue route and want to Sneak Attack after your opponent is grappled and prone, this lets you do that without giving up your shield. Advantage against being charmed and frightened is also useful. The only reason this isn't gold is Natural Armor being mostly useless.
Simic Hybrid. +2/+1 and unfortunately a trap. The appendages sound like sky blue or even gold, until you read the limitations. First, to grapple with them specifically, you burn your entire action; terrible. The on-hit grapple sounds much better but it suffers from the Tavern Brawler syndrome: at best you're sacrificing a grapple attemp for an attack and a chance for the grapple attempt you gave up for it, since it calls for a hit specifically, which means a successful attack roll is required. This means at best you're even in action economy in regards to total grapple/shove attemps specifically, and at worst you wasted a grapple attempt. The build's focus is not damage and attack rolls; you'll have many, many more options for using your bonus action anyway, especially after level 3.
Tabaxi. +2/+1, Darkvision, Feline Agility and 1d4 unarmed. Three luxury features don't make a blue but do earn a place on the list, especially since it has the potential to become blue if your DM allows jumping shenanigans; read more about that further below, in the Bard path section about Longstrider.
Tiefling, winged. +2/+1, Darkvision, fire resistance, 30ft fly speed and can still wear medium armor. You can, in fact, get 14 DEX with this build so if you really, really want that flight, this is your option. It lets you be useful against flying enemies without magic items or spells; the resistance is a reasonable trade-off for the -1 AC compared to heavy armor, especially since fire is a rather common damage type. Shoving flying enemies prone immediately makes them fall and take appropriate fall damage, keep that in mind.
Yuan-Ti Pureblood. +2/+1, Darkvision, Magic Resistance and Poison Resistance. Saves and resistances are second on the priority list and this one has plenty.
Background doesn't matter, you only really need Athletics and Rune Knight already has you covered. Anything else is luxury.
Feats
As far as ASIs go, you'll get five total for sure, with an optional 6th. One or two of these will ideally be +2 STR upgrades.
Shield Master. Lack of Eldritch Knight means you don't have the opportunity to spam Shield or Absorb Elements once per round; using a shield can at least fix one of those shortcomings, somewhat. Later you get the opportunity to dip into Sorcerer for those two spells but that's around level 13. Shield Master is the only feat that boosts your DEX save while letting you pick Resilient (WIS) as well, this alone puts it into gold territory. The action economy boost is actually fine for a build that doesn't focus on damage, even after the ruling change. How the DM interprets the sequence isn't even relevant since ideally you'll perform ability checks only, as your party capitalizes on the advantage. The reaction is a nice option, too. If you find a magical shield with an AC boost, that boost applies to your DEX save as well, thanks to this feat. This means that in theory, Shield Master can grant you up to +5 to DEX saves. In fact, should you dip a level into Forge Cleric you can boost your shield for a +1 to DEX save with this feat.
Resilient (WIS). Wisdom saves are generally save-or-suck. You can't suck and grapple at the same time, unless you're playing a FATAL game or something similar, I guess. If you're taking this thread's name literally, you'll need a good Wisdom save against the Tarrasque too.
War Caster. Rune Knight already gives us proficiency in CON saves and the Hill Rune will grant us some resistances for halved dmage and, by proxy, concentration check DCs. War Caster essentially ensures your concentration will never be seriously challenged, even against damage types you don't resist.
Alert. A flat +5 to initiative is wonderful for a playstyle that works better the earlier it is on the list. Never getting surprised again and an anti-invisibility buff on top of that makes for a solid pick.
Lucky. This feat is a great addition to any build. Save the luck dice for crucial saves and initiative rolls. If you really don't want to use a shield, this is the best feat to replace Shield Master with.
Athlete. This feat is more important for grappling builds that drop creatures from high places for fall damage but it does have some nice features regardless. There's an interesting possibility of a jumping method for granting prone status to creatures with just your movement; read more about that further below, in the Bard path section about Longstrider. Case in point, sometimes Longstrider isn't enough; races with 25ft base speed who can't reach a height of 6ft, specifically. Athlete fixes that by reducing the running start distance of high jumps by 5ft. This also decreases the chance of this maneuver triggering opportunity attacks; the jump itself is short enough to not move you out of reach but the running start requirement might. The additional 5ft stand-up is a nice insurance for the occasional failed STR save and similar; even better, this is a half-feat, granting +1 STR. It can also open up opportunities for climbing shenanigans; not bad but certainly situational, which is why it remains blue instead of sky blue, even if the jumping tactic is allowed.
Mobile. This feat will likely compete with Athlete, as it can also fix the 25ft-speed races' movement shortcomings. If you don't care about climbing shenanigans, the quick-stand feature and the +1 STR, this is certainly a better pick.
Mage Slayer. When this works, it works wonders. Very situational and hard to fit into the build.
Grappler. Strictly for parties with majority ranged attack and/or DEX-save DPR.
Tavern Brawler. This is a trap; 1d4 unarmed is a luxury feature and the grapple attempt is on a hit, not on an attack. This means at best you're even on action economy for grappling and shoving purposes, and at worst you wasted an attempt. Damage is not this build's priority and Tavern Brawler isn't even worth a half-feat for this exact reason.
Class Progression
There are a few significant milestones any good grappler build will want to reach:
Extra Attack, even for transforming grapplers because multiattack doesn't let you grapple/shove multiple times. This essentially means you'll commit at least 5 levels into Rune Knight.
Expertise. A feat tax, Bard, Ranger or Rogue multiclass are your options here. Considering both Rogue and Bard has good features besides expertise, including Enlarge which you also need, those are preferred over the feat tax and Ranger.
Advantage on Athletics checks. Rune Knight already has this covered, from level 3 on.
Size buff for staying relevant against huge cretaures. Once again, Rune Knight has this covered by the time you reach level 3.
This is why Rune Knight is a great base for grapplers. Eldritch Knight can cover these by the time you reach level 8 as well, and has several spells you can utilize for better survivability but can never get past the limit of huge creature size. That's the trade-off Rune Knight offers, as well as faster offensive scaling, as long as grappling is involved.
Keep one thing in mind: during the first two levels you'll be better off dealing damage than grappling/shoving with your action. Your Athletics bonus is low, enemy health pools are also low; it's just more efficient to beat them up instead.
Fighter 1, you pick up Athletics proficiency if you don't already have it.
Second Wind is a welocme addition, especially at lower levels.
Fighting Style options:
Interception. Incredible at lower levels, ask your DM if you can switch Fighting Styles when you gain an ASI; if the answer is yes, this is a no-brainer.
Defense. Good old +1 AC, as solid as ever.
Unarmed Fighting. If you chose a race without unarmed damage dice, this can fix your unarmed damage. Past level 4 you really shouldn't be using unarmed strikes, though; you'll be grappling and shoving instead. Sadly the 1d4 grapple damage happens at the beginning of your turn, which means the creature not only has to fail the initial grapple roll, then the escape attempt, but also has to be still alive after a whole round of your allies beating it up with advantage; all that for 1d4 extra damage. Pathetic but definitely better than nothing.
Fighter 2 will grant you Action Surge. We both know how good that is, 'nuff said.
Rune Knight 3; you reach your first power spike: Giant's Might. This is essentially Enlarge, except it can't be dispelled, it spares your action, it doesn't need a concentration save and you get two uses of it at level 3, like if you were Wizard 3. The only difference is the bonus damage applying to only one attack; hardly a problem before level 5, at which point you'll be rolling ability checks, not attack rolls.
You also get to choose two runes. Choose wisely, as you'll only get 4 total in this build! Your options are:
Frost Rune. Hands down the best you can choose at this point for a grappler. +2 to STR and CON ability checks and saves, for 10 minutes, with a bonus action activation, once per short rest. The long duration means you can comfortably pop this before you engage in combat, provided you know danger lies ahead.
Fire Rune. An extra 2d6 damage is not bad at level 3; an additional chance for a really good debuff is even better; and it has no action economy cost to activate, now that's nice! Short rest recharge, like all runes. Only downside being, you'll rarely make attack rolls after level 5. It's still nice for an option.
Cloud Rune. Once per short rest, you can redirect an attack, without a save, and anyone within 30ft of you is fair game, regardless if the attack was melee or ranged. This ability works against spells that use attack rolls. This ability works on attacks rolls you or your allies make. The tactical applications of this thing are limitless, you can hit the tank and miss but actually hit the enemy mage hiding behind the tank because you used this ability. An ally misses a powerful attack roll-based spell against the BBEG, you can redirect it to the BBEG's bulky bodyguard who has lower AC to save the otherwise wasted damage nuke. You can force an attack to hit the party tank (likely you) even if the enemies actively ignore the tank.
At Rune Knight 4 you gain an ASI. My personal advice would be to pick a gold feat.
Level 5 gives you Extra Attack and a 3rd daily use of Giant's Might, serving as your second power spike.
Now you can choose whether you go Rune Knight 6 for a fast ASI to pick up the gold feat you didn't choose at level 4 or do it later and begin your multiclass progression. You have two choices: Bard or Rogue. You'll likely have to make this choice during character creation since your ability scores are the main bottleneck for multiclassing.
The Bard Path
The Bard path will delay your Expertise to Bard 3 but you get Enlarge at the same time along with it. You'll only ever have one inspiration die (unless you traded CON for CHA and WIS during character creation); consider it a sort of roll manipulation for times when you really, really want something to happen. The various spells will broaden your party-wide utility value.
Bard 1 is the standard toolkit.
Bardic Inspiration, mostly for out-of-combat utility, for now. You likely only get one die and you can't use it yourself; pretty lackluster so far.
You get access to spells like Healing Word and Longstrider. This grants you some nice utility.
An important thing about Longstrider: it can be gold, as long as you can convince your DM of a specific interaction's validity. PHB, pg. 192 mentions jumping rules, more importantly high jumps and that a character has a reach of the jump's height plus 1½ of the character's own height. This is due to the jump height being calculated as the distance between the ground and your feet; what's important here is you can extend your arms for ½ your height for further reach. If you can convince your DM that you raise your grappled target by this amount as you jump, this opens up a powerful new tactic.
A high jump with a running start will have a height of 3 + your STR modifier in feet. For this build, that floats between 6 and 8. This means even 4ft high characters can reach 10ft high jumps imposed on their grappled targets, as long as they can jump 8 feet high. Jumping is followed by falling the same distance down; a 10ft fall causes 1d6 fall damage and the creature falls prone. That's a guaranteed prone from just using your movement!
Now, what does Longstrider have to do with this? The running start is 10ft of movement; actually 20ft if you're grappling. If your character is at least 4ft tall, they can get away with jumping 8ft; 16ft movement. That's 34ft movement total; Longstrider gives you +10ft. Creatures with 25ft base movement can still do this if they're at least 6ft tall; Rune Knight 10 makes you grow up to 3d4 inches, this can be a gamechanger for small creatures and dwarves. Alternatively, pick up the Athlete feat for 5ft running start and climbing shenanigans.
At Bard 2 you get Jack of All Trades. This boosts your initiative. You also get Song of Rest.
You go Lore Bard 3 for the next level and reach your third power spike. This grants you:
Cutting Words. Now you can use your own Inspiration die. Make it count.
Expertise. A direct grappling boost.
The spell Enlarge; since Tasha's, this spell is on the Bard's spell list! Now you're a certified Tarrasque Tackler, although your stats aren't there just yet. If your DM doesn't like that and won't let you get Enlarge, you can pick it up at Lore Bard 6 anyway; in that case you should grab Enhance Ability instead.
Lore Bard 4 will grant you an ASI and thus I highly advise picking it up, although it's not mandatory at all. If you rushed Rune Knight 6, you should consider Alert, Lucky or War Caster, latter being the better pick unless you're planning on a 2-level dip into Druid at some point. See dips further down below.
Lore Bard 5 is optional; it boosts your Bardic Inspiration to blue status by increasing the die to d8 and allowing a short rest recharge. Still likely just one die and will remain so; use it wisely.
Lore Bard 6 is only for those games where the DM doesn't like Tasha's giving Enlarge to Bards. You gain access to Enlarge and one additional spell of your choice. Decent choices include Shield, Absorb Elements and Hex.
A better alternative is a Sorceror dip for those reaction spells. See dips further below.
Now you'll go back to Rune Knight. I'll assume you already got Rune Knight 6, so let's jump to 7: You get to choose a new rune! This is your fourth power spike.
Hill Rune is half a Rage plus a Dwarf racial bonus, that recharges with a short rest. The resistances will massively help your concentration saves by nuking the DC, as well as preserve your hit points. Awesome choice and is what I'd pick up first.
Storm Rune is a third of the Alert feat and an on-demand advantage or disadvantage, once per round, using your reaction, for 10 rounds. It can affect anyone within 60ft of you and can manipulate essentially any d20 roll. Your spellcasters will love you; disadvantage on save-or-suck spells, including every time the poor target attempts a new save, is just hilarious. Oh, did I mention it recharges every short rest?
Rune Knight 8 gives you an ASI. Consider a +2 STR or a sky blue feat. You can function well even with 16 STR and you'll get one more ASI guaranteed, even up to two more if you don't dip into other classes too much.
Rune Knight 9 introduces Indomitable, a.k.a. second chance for a failed save. If you have the Lucky feat and aren't afraid to spam the luck dice this can essentially grant you highest of 4d20 on one save per day, or even better if you already had advantage on the save (that specific instace grants you highest of 6d20, respectively). That one interaction with Lucky is more than enough reason to consider the feat.
Rune Knight 10 lets you pick up your last rune which will essentially be either Hill or Storm, whichever you didn't pick up at Rune Knight 7. You'll also grow taller and gain an upgrade to essentially the only feature of Giant's Might that you don't care much about.
Rune Knight 11 is your fifth power spike, with Extra Attack 2.
Rune Knight 12 grants you an ASI.
After you got to Rune Knight 7 / Lore Bard 3 at the very least (or Lore Bard 6 if that's how you got Enlarge), you can dip at any point. Here are your options for the build's end-game:
Rune Knight 14 / Lore Bard 5 for more Indomitable, an ASI and dip one level into a third class.
Rune Knight 15 / Lore Bard 5 for more Indomitable, an ASI and Rune Knight 15 which now grants you two uses of your runes per short rest, as well as a 5th rune choice!
Rune Knight 15 / Lore Bard 4 for the same deal as above but trading your Bardic Inspiration upgrade for a dip into a third class.
Rune Knight 15 / Lore Bard 3 for keeping the awesome Rune Knight 15 boosts but trading Inspiration upgrade and an ASI for two levels to dip into other classes.
Rune Knight 13 / Lore Bard 5 for more Indomitable but trading an ASI and Rune Knight 15 for two levels to dip in other classes.
Any further combinations, as long as you have at least Rune Knight 13 / Lore Bard 3. You have plenty of good options for dips; it'll be up for you to choose what you are willing to give up for them.
Bard Spells
Avoid attack roll or save based spells, including cantrips. You'll have at best 14 CHA; that's just not good enough. In addition, concentration spells compete with Enlarge when you're fighting gargantuan ceratures. Having said that, Bard spells to consider learning are the following:
Light, cantrip. This can help if you don't have Darkvision. Cast it on a pebble and throw for a situational distraction.
Prestidigitation, cantrip. Chilling and warming objects can be useful in a survival situation and can create a heat source without light. Alternatively, light a campfire easily.
Cure Wounds, 1st. You're not the party healer but when DMs penalize pop-up healing via Healing Word, you can use this outside combat for a bit better mileage.
Feather Fall, 1st. Good for insurance but a bit too specific.
Healing Word, 1st. As useful as ever. Always nice to be able to one-up the Cleric and make the DM wonder who to focus in combat.
Heroism, 1st. Concentration. Immunity against being frightened is great.
Longstrider, 1st. Becomes gold if you can use the jump-prone tactic. A useful buff with long duration.
Enhance Ability, 2nd. Concentration. Outside of buffing allies' ability checks, it's useful for one more reason: when the party decides to use Stealth, you can cancel your armor's disadvantage.
Enlarge, 2nd. Concentration. This is what lets you grapple gargantuan creatures when combined with Giant's Might.
Heat Metal, 2nd. Concentration. This spell doesn't have a save when you cast it on armor and provides a great debuff. You can also cast it on a weapon to disarm someone. The only downside is it takes your bonus action. It also does some damage.
Silence, 2nd. Concentration. There are less than 30 spells total that don't use verbal components, across all official 5e sources, and less than 20 of those are 1st level or higher. You're already a frontliner, go grapple those mages and cast this. At best, they become useless. At worst, they escape the grapple, stand up and move 15-20 ft away from you, still being in Silence's radius. They can't even Dispel it without an ally doing it for them, since that also has a verbal component. Most spellcasters aren't gargantuan, which means you tend to be able to affort casting Silence when you need it.
Catnap, 3rd. If your allies frequently find themselves in a need of a short rest with less than an hour but more than 10 minutes to share, this can be useful. That situation is extremely rare, however.
Dispel Magic, 3rd. This is a trap. It would be good if you could upcast it. You can't, so stay far away from it.
Glyph of Warding, 3rd. This is gold if you're in a game where defending an area or structure is the most important element, you get at least a few hours to prepare, and you have enough money to afford this spell. With careful triggers you can set up a few buffs and even heals for yourself and/or your allies with zero action economy footprint in combat. Quite useless in most other circumstances.
Motivational Speech, 3rd. For those times when you are going to fight a gargantuan creature very soon and you want some sort of party-wide buff to WIS saves. Not really good but at least it's something; it's not blue because it doesn't affect you, only your allies.
The Rogue Route
The Rogue route grants you Expertise at Rogue 1 but delays Enlarge to Rogue 8. This is a much longer multiclass commitment and the delay on Enlarge is mainly the reason it's blue, as well as Sneak Attack being completely useless for both grappling and unarmed strikes. This changes drastically if you can convince your DM to let you use a finesse dagger built into your boot or something similar you can kick with that qualifies, however it does mean you're wasting a grapple/shove opportunity on an attack. The immediate Expertise you gain does mean you might end up with "free" attacks more often after you're done with your usual skill check rotation.
Rogue 1 has Expertise, your third power spike.
Rogue 2 grants Cunning Action, a luxury feature that lets you drag creatures twice as far for a bonus action, enabling all kinds of shenanigans. Blue only because you already have massive competition for your bonus action, even if you didn't pick up Shield Master.
Arcane Trickster 3 for the archetype. The spells will be mostly illusions, in addition to whatever you can get away with that grants some utility. Your spell DC will suck, don't even think about combat value until level 8.
Arcane Trickster 4 grants you an ASI. Consider a sky blue feat.
Since this multiclass sequence takes longer to finish, feel free to pick up Rune Knight 7 around between Arcane trickster 4 and 5 for your fourth power spike. I recommend Hill rune; see the Bard path for details on the runes.
Arcane Trickster 5 is Uncanny Dodge time, a decent defensive option that can cover attack damage types your Hill Rune does not.
Arcane Trickster 6 is essentially a dead level; you don't really need more Expertise in combat but the Rogue route can fill quite a few out-of-combat roles so not completely useless.
Arcane Trickster 7 grants Evasion, meaning you don't have to use your bonus action on Shield Master ever again.
Arcane Trickster 8 finally grants you Enlarge, bringing about your fifth power spike and enabling your gargantuan grappling game.
I don't recommend going for Reliable Talent. Too many dead levels without significant features and having advantage already means you'll roll under 10 only 20,25% of the time. It's nice for insurance but the opportunity cost is massive; we're talking about no Indomitable, no Extra Attack 2 and no fourth Rune. Don't do it.
So, Rune Knight 8. That's an ASI. It's your last guaranteed one, keep that in mind. By now you ideally have both gold feats and two or even three sky blue feats.
Rune Knight 9 grants you Indomitable. See the Bard path for a detailed praise of this ability.
Rune Knight 10 is the point where you pick up the Hill or Storm Rune, whichever you didn't grab at Runic Knight 7. You also grow a bit in height and get a bit better damage during Giant's Might.
Rune Knight 11 is your sixth power spike as you gain Extra Attack 2.
After you've reached Rune Knight 7 / Arcane Trickster 8, you can plan out the build's end-game. You can dip any time after that point; here are your options:
Rune Knight 12 / Arcane Trickster 8 for an ASI.
Rune Knight 11 / Arcane Trickster 8 and a one level dip into a third class.
Dip Tips
Any class not on this list is either not worth considering or you can't dip into due to the ability score array.
Barbarian, 13 STR. Two levels or none, you're here for Danger Sense. Not really worth giving up an ASI and a second Indomitable use but if you want it, you can certainly have it.
Cleric, 13 WIS. One level only. Forge Domain for Blessing of the Forge. Now, normally this is just a +1 AC but if you have Shield Master and your shield is still nonmagical, this bonus becomes +1 AC and +1 DEX save. That's much better! Peace Domain for Emboldening Bond which is a no-concentration Bless that lasts for 10 minutes, can also boost ability checks, including initiative, but only grants 1d4 once per turn and requires buddies to be within 30ft of each other. Number of uses scales with proficiency; this thing was practically made for multiclass dips. It also stacks with actual Bless and grants the Rogue route access to Healing Word.
Druid, 13 WIS. Two levels or none. Wild Companion can grant advantage to party members with the Help action. Circle of Stars grants Starry Form which can give you a Reliable Talent effect for your concentration saves! This is very good if you don't want to pick up War Caster, it's an adequate replacement but otherwise overkill.
Sorcerer, 13 CHA. One level only. Pick up Shield and Absorb Elements. Clockwork Soul has Restore Blalance, an incredibly situational die manipulation option. Divine Soul gets Favored by the Gods, a once-per-short-rest save boost of 2d4. That is pretty good, a high chance of getting a 4-6 on the roll. Consistency is king in the realm of RNG, this is gold.
Warlock, 13 CHA. One level only. Pact of the Talisman can grant you an additional 1d4 to your ability check whenever you would fail; uses scale with proficiency. Gain access to Hex. Celestial Patron grants Healing Light for some utility. Invocation can be Devil's Sight for that magical Darkvision or Fiendish Vigor to have your entire party start every battle with 1d4+4 more health. A solid pick with more party utility focus than Sorcerer.
Paladin, 13 STR and 13 CHA. Two levels or none. Smite, Lay on Hands with 10 hit point pool and a second Fighting Style. If you feel your party needs damage and you want to fill that need, this is the dip for you. Smite lets you do significant burst damage with just one attack which doesn't hurt your action economy too much, and you can pick up Blind Fighting, Dueling (if your DM allows that to work with unarmed strikes) or Defense.
This build attempts to achieve two things.
Be able to grapple gargantuan creatures.
Achieve this without transformation, using Rune Knight's Giant's Might.
This will be a pure grapple/shove build; damage is not the focus, enabling the rest of the party is. The general priority:
Reaching peak grappling potential. Advantage, size buff, general roll manipulation and Athletics bonuses.
AC, saves, damage resistance, hit points. You can't do your job when you're dead.
Party utility. Anything that isn't direct damage but doesn't only benefit you specifically to do your job.
Damage. It's not the focus of the build, therefore it's last on the list.
Colour Code:
Gold: Icredible stuff.
Sky Blue: Great feature.
Blue: Useful option.
Black: Meh. Not good, not bad.
Red: It's a trap or just straight-out bad.
Green: Situational.
Point Buy Array
15, 14, 13, 12, 10, 8 is our go-to choice. 15, 14 can become 16, 16 with a +2/+1 race; those two will be STR and CON, respectively. The 13 lets us multiclass into either Bard or Rogue for Expertise and Enlarge. A +2/0 race would drop the 15 to a second 14, sacrificing a CON bonus to put the points elsewhere. INT is the preferred dump stat, if you're not going to multiclass into CHA classes feel free to drop that to 8 as well. The build itself is rather MAD not strictly due to multiclass but because we really want high initiative, CON and WIS saves on top of ideally 20 STR.
That being said, if you'll absolutely pick up War Caster at one point it's not a terrible idea to drop CON to 14, even with a +2/+1 race; the extra points can bump WIS to 13 (which will become 14 later on), as well as DEX to 12 (or 14 if you dumped CHA as well); alternatively CHA 14 instead of DEX 12 if you want two Bardic Inspiration dice. This will leave one point that you can put anywhere since it'll be utterly inconsequential. You trade a +1 CON bonus and up to 20 hit points total for +1 WIS and +1 DEX/CHA bonuses; buffing your weaker saves and/or adding utility, the trade-off is valid and will come down to personal preference.
Race Choices
I'm not going to mention stuff like Water Genasi drowning creatures with grappling underwater or Aarakocra dropping creatures for damage. This is a party enabler build, damage and kill speed are not your concerns, you have the rest of your party for that. Small races can still reach the coveted huge size; Giant's Might upgrades size to large instead of just increasing the size category. Small races will rely on Giant's Might much more than medium ones; this does mean they are better suited for the Rogue route since Enlarge doesn't let them save Giant's Might uses for later, thus it doesn't hurt as much if Enlarge acquisition is delayed. Let's dive in:
Bugbear. +2/+1, Darkvision and Powerful Build; latter only for DMs who insist on push/drag/lift weight rules for moving grappled creatures. The reach is useless for grappling, unfortunately; its duration is strictly between the beginning and the end of the attack itself, which means grapple breaks the moment you conclude the grapple contest, regardless of outcome, if the target wasn't within 5ft. Still useful for shoving but its utility is very limited overall.
Centaur. +2/+1, 40ft speed, 1d4 unarmed and Equine Build which is Powerful Build with a situational mobility penalty you can ignore 99% of the time during your grappling shenanigans. One ruling insurance and two luxury features make this blue. This one becomes sky blue if your DM allows jumping shenanigans; read more about that further below, in the Bard path section about Longstrider.
Custom Lineage. +2/0, Darkvision and an early feat. I'd rather pick a +2/+1 race but there's one specific circumstance where I wouldn't even think before picking this: when the majority of my party is using ranged attacks and/or DEX-save based abilities. The extra feat lets you pick up Grappler at first level, or alternatively Shield Master for the shove which you can use to widen the gap between friends and foes instead of shoving prone. Point in case, the extra feat lets you grab Grappler without losing out on other, generally better feats.
Duergar. +2/+1, Superior Darkvision, Duergar Resilience, once-per-day Enlarge at level 3 which is mostly overkill but still very nice, once-per-day Invisibility at level 5 for utility and the weapon proficiencies can be traded in for even more tool proficiencies to turn you into a swiss army knife. Even better, you couldn't care less about Sunlight Sensitivity; grapples and shoves are not attack rolls and you have your party for Perception checks. The Alert feat can negate the one true danger of perception disadvantage anyway. The 25ft speed stings a bit but for this package it's a perfectly acceptable trade-off. Still not sold? +1 STR and +2 CON means you don't really care whether the DM allows Tasha's optional custom origin rule (but if they don't, you can't do the 14 CON trade-off), the array will work for you regardless.
Gnome, deep. +2/+1, Superior Darkvision and Gnome Cunning makes this small race a fine choice if you're looking for this combination specifically. If you're fine with standard Darkvision, Yuan-Ti Pureblood is simply better in every way; that being said, if Yuan-Ti Pureblood is banned at the table (it likely is), this is your go-to choice for WIS save advantage and consider it sky blue.
Goliath. +2/+1, cold resistance, Powerful Build and Stone's Endurance. Latter is especially powerful during lower levels, it's essentially an extra HD you can roll during combat throughout the game. What really sells this ability is the damage decrease directly translates into a lower concentration save as well, at least once things start hitting hard, and is applied after resistances! +2 STR and +1 CON means this race can also perform well if Tasha's optional rule isn't allowed.
Halfling, lotusden. +2/+1. Lucky, Brave and Spike Growth; the first two are nice features that can help with saves as well, latter is the only way you can pick up Spike Growth in this build. Damage is not a priority but this grants you the option to lay down some serious hurt; Giant's Might leaves your concentration slot for other things, this is a fine candidate. You can drag grappled creatures back and forth through Spike Growth to deal 4d4 damage every turn with just your movement alone. Longstrider will increase this by 2d4, Mobile grants another 2d4 on top of that. You can dash to double that total for up to 16d4. If you can dash as a bonus action and as an action at once, you can do up to 24d4 damage per turn. That's 60 magical piercing damage on average; no save, no attack roll, deal with it. Of course, you still have to grapple the victim first. Once per day but still nice; a Druid or Ranger can also cast this for you, turning this into blue if that's an option, sky blue if it's not.
Kobold. +2/0. This is a potential trap new players might fall into: ability checks are not attack rolls, making Pack Tactics useless!
Half-Orc. +2/+1; honestly on the list only because +2 STR and +1 CON means you don't rely on Tasha's optional rule. Darkvision and Relentless Endurance aren't useless but just aren't enough to make this race compete with the rest.
Hobgoblin. +2/+1, Darkvision and Saving Face, which is a once-per-short-rest die manipulation of up to +5 bonus on essentially any d20 roll of yours that you would otherwise fail, including even death saves. This alone is a worthwhile investment as you can hold this for crucial saves or other rolls. A nice DM will let you know whether you can use this to change the outcome before you commit, otherwise it's still a gamble. Hire some mercenaries, commoners or get sidekicks to max the bonus if your total party size is lower than 6. Pets, familiars and animal companions also count, as long as they aren't invisible. The armor and weapon proficiencies can be turned into tool proficiencies for utility.
Loxodon. +2/+1, Powerful Build and an extra appendage you can grapple with. If you want to grapple more than one creature at once and you want to use a shield as well (you really should), this is your best option. If you want to go the Rogue route and want to Sneak Attack after your opponent is grappled and prone, this lets you do that without giving up your shield. Advantage against being charmed and frightened is also useful. The only reason this isn't gold is Natural Armor being mostly useless.
Simic Hybrid. +2/+1 and unfortunately a trap. The appendages sound like sky blue or even gold, until you read the limitations. First, to grapple with them specifically, you burn your entire action; terrible. The on-hit grapple sounds much better but it suffers from the Tavern Brawler syndrome: at best you're sacrificing a grapple attemp for an attack and a chance for the grapple attempt you gave up for it, since it calls for a hit specifically, which means a successful attack roll is required. This means at best you're even in action economy in regards to total grapple/shove attemps specifically, and at worst you wasted a grapple attempt. The build's focus is not damage and attack rolls; you'll have many, many more options for using your bonus action anyway, especially after level 3.
Tabaxi. +2/+1, Darkvision, Feline Agility and 1d4 unarmed. Three luxury features don't make a blue but do earn a place on the list, especially since it has the potential to become blue if your DM allows jumping shenanigans; read more about that further below, in the Bard path section about Longstrider.
Tiefling, winged. +2/+1, Darkvision, fire resistance, 30ft fly speed and can still wear medium armor. You can, in fact, get 14 DEX with this build so if you really, really want that flight, this is your option. It lets you be useful against flying enemies without magic items or spells; the resistance is a reasonable trade-off for the -1 AC compared to heavy armor, especially since fire is a rather common damage type. Shoving flying enemies prone immediately makes them fall and take appropriate fall damage, keep that in mind.
Yuan-Ti Pureblood. +2/+1, Darkvision, Magic Resistance and Poison Resistance. Saves and resistances are second on the priority list and this one has plenty.
Background doesn't matter, you only really need Athletics and Rune Knight already has you covered. Anything else is luxury.
Feats
As far as ASIs go, you'll get five total for sure, with an optional 6th. One or two of these will ideally be +2 STR upgrades.
Shield Master. Lack of Eldritch Knight means you don't have the opportunity to spam Shield or Absorb Elements once per round; using a shield can at least fix one of those shortcomings, somewhat. Later you get the opportunity to dip into Sorcerer for those two spells but that's around level 13. Shield Master is the only feat that boosts your DEX save while letting you pick Resilient (WIS) as well, this alone puts it into gold territory. The action economy boost is actually fine for a build that doesn't focus on damage, even after the ruling change. How the DM interprets the sequence isn't even relevant since ideally you'll perform ability checks only, as your party capitalizes on the advantage. The reaction is a nice option, too. If you find a magical shield with an AC boost, that boost applies to your DEX save as well, thanks to this feat. This means that in theory, Shield Master can grant you up to +5 to DEX saves. In fact, should you dip a level into Forge Cleric you can boost your shield for a +1 to DEX save with this feat.
Resilient (WIS). Wisdom saves are generally save-or-suck. You can't suck and grapple at the same time, unless you're playing a FATAL game or something similar, I guess. If you're taking this thread's name literally, you'll need a good Wisdom save against the Tarrasque too.
War Caster. Rune Knight already gives us proficiency in CON saves and the Hill Rune will grant us some resistances for halved dmage and, by proxy, concentration check DCs. War Caster essentially ensures your concentration will never be seriously challenged, even against damage types you don't resist.
Alert. A flat +5 to initiative is wonderful for a playstyle that works better the earlier it is on the list. Never getting surprised again and an anti-invisibility buff on top of that makes for a solid pick.
Lucky. This feat is a great addition to any build. Save the luck dice for crucial saves and initiative rolls. If you really don't want to use a shield, this is the best feat to replace Shield Master with.
Athlete. This feat is more important for grappling builds that drop creatures from high places for fall damage but it does have some nice features regardless. There's an interesting possibility of a jumping method for granting prone status to creatures with just your movement; read more about that further below, in the Bard path section about Longstrider. Case in point, sometimes Longstrider isn't enough; races with 25ft base speed who can't reach a height of 6ft, specifically. Athlete fixes that by reducing the running start distance of high jumps by 5ft. This also decreases the chance of this maneuver triggering opportunity attacks; the jump itself is short enough to not move you out of reach but the running start requirement might. The additional 5ft stand-up is a nice insurance for the occasional failed STR save and similar; even better, this is a half-feat, granting +1 STR. It can also open up opportunities for climbing shenanigans; not bad but certainly situational, which is why it remains blue instead of sky blue, even if the jumping tactic is allowed.
Mobile. This feat will likely compete with Athlete, as it can also fix the 25ft-speed races' movement shortcomings. If you don't care about climbing shenanigans, the quick-stand feature and the +1 STR, this is certainly a better pick.
Mage Slayer. When this works, it works wonders. Very situational and hard to fit into the build.
Grappler. Strictly for parties with majority ranged attack and/or DEX-save DPR.
Tavern Brawler. This is a trap; 1d4 unarmed is a luxury feature and the grapple attempt is on a hit, not on an attack. This means at best you're even on action economy for grappling and shoving purposes, and at worst you wasted an attempt. Damage is not this build's priority and Tavern Brawler isn't even worth a half-feat for this exact reason.
Class Progression
There are a few significant milestones any good grappler build will want to reach:
Extra Attack, even for transforming grapplers because multiattack doesn't let you grapple/shove multiple times. This essentially means you'll commit at least 5 levels into Rune Knight.
Expertise. A feat tax, Bard, Ranger or Rogue multiclass are your options here. Considering both Rogue and Bard has good features besides expertise, including Enlarge which you also need, those are preferred over the feat tax and Ranger.
Advantage on Athletics checks. Rune Knight already has this covered, from level 3 on.
Size buff for staying relevant against huge cretaures. Once again, Rune Knight has this covered by the time you reach level 3.
This is why Rune Knight is a great base for grapplers. Eldritch Knight can cover these by the time you reach level 8 as well, and has several spells you can utilize for better survivability but can never get past the limit of huge creature size. That's the trade-off Rune Knight offers, as well as faster offensive scaling, as long as grappling is involved.
Keep one thing in mind: during the first two levels you'll be better off dealing damage than grappling/shoving with your action. Your Athletics bonus is low, enemy health pools are also low; it's just more efficient to beat them up instead.
Fighter 1, you pick up Athletics proficiency if you don't already have it.
Second Wind is a welocme addition, especially at lower levels.
Fighting Style options:
Interception. Incredible at lower levels, ask your DM if you can switch Fighting Styles when you gain an ASI; if the answer is yes, this is a no-brainer.
Defense. Good old +1 AC, as solid as ever.
Unarmed Fighting. If you chose a race without unarmed damage dice, this can fix your unarmed damage. Past level 4 you really shouldn't be using unarmed strikes, though; you'll be grappling and shoving instead. Sadly the 1d4 grapple damage happens at the beginning of your turn, which means the creature not only has to fail the initial grapple roll, then the escape attempt, but also has to be still alive after a whole round of your allies beating it up with advantage; all that for 1d4 extra damage. Pathetic but definitely better than nothing.
Fighter 2 will grant you Action Surge. We both know how good that is, 'nuff said.
Rune Knight 3; you reach your first power spike: Giant's Might. This is essentially Enlarge, except it can't be dispelled, it spares your action, it doesn't need a concentration save and you get two uses of it at level 3, like if you were Wizard 3. The only difference is the bonus damage applying to only one attack; hardly a problem before level 5, at which point you'll be rolling ability checks, not attack rolls.
You also get to choose two runes. Choose wisely, as you'll only get 4 total in this build! Your options are:
Frost Rune. Hands down the best you can choose at this point for a grappler. +2 to STR and CON ability checks and saves, for 10 minutes, with a bonus action activation, once per short rest. The long duration means you can comfortably pop this before you engage in combat, provided you know danger lies ahead.
Fire Rune. An extra 2d6 damage is not bad at level 3; an additional chance for a really good debuff is even better; and it has no action economy cost to activate, now that's nice! Short rest recharge, like all runes. Only downside being, you'll rarely make attack rolls after level 5. It's still nice for an option.
Cloud Rune. Once per short rest, you can redirect an attack, without a save, and anyone within 30ft of you is fair game, regardless if the attack was melee or ranged. This ability works against spells that use attack rolls. This ability works on attacks rolls you or your allies make. The tactical applications of this thing are limitless, you can hit the tank and miss but actually hit the enemy mage hiding behind the tank because you used this ability. An ally misses a powerful attack roll-based spell against the BBEG, you can redirect it to the BBEG's bulky bodyguard who has lower AC to save the otherwise wasted damage nuke. You can force an attack to hit the party tank (likely you) even if the enemies actively ignore the tank.
At Rune Knight 4 you gain an ASI. My personal advice would be to pick a gold feat.
Level 5 gives you Extra Attack and a 3rd daily use of Giant's Might, serving as your second power spike.
Now you can choose whether you go Rune Knight 6 for a fast ASI to pick up the gold feat you didn't choose at level 4 or do it later and begin your multiclass progression. You have two choices: Bard or Rogue. You'll likely have to make this choice during character creation since your ability scores are the main bottleneck for multiclassing.
The Bard Path
The Bard path will delay your Expertise to Bard 3 but you get Enlarge at the same time along with it. You'll only ever have one inspiration die (unless you traded CON for CHA and WIS during character creation); consider it a sort of roll manipulation for times when you really, really want something to happen. The various spells will broaden your party-wide utility value.
Bard 1 is the standard toolkit.
Bardic Inspiration, mostly for out-of-combat utility, for now. You likely only get one die and you can't use it yourself; pretty lackluster so far.
You get access to spells like Healing Word and Longstrider. This grants you some nice utility.
An important thing about Longstrider: it can be gold, as long as you can convince your DM of a specific interaction's validity. PHB, pg. 192 mentions jumping rules, more importantly high jumps and that a character has a reach of the jump's height plus 1½ of the character's own height. This is due to the jump height being calculated as the distance between the ground and your feet; what's important here is you can extend your arms for ½ your height for further reach. If you can convince your DM that you raise your grappled target by this amount as you jump, this opens up a powerful new tactic.
A high jump with a running start will have a height of 3 + your STR modifier in feet. For this build, that floats between 6 and 8. This means even 4ft high characters can reach 10ft high jumps imposed on their grappled targets, as long as they can jump 8 feet high. Jumping is followed by falling the same distance down; a 10ft fall causes 1d6 fall damage and the creature falls prone. That's a guaranteed prone from just using your movement!
Now, what does Longstrider have to do with this? The running start is 10ft of movement; actually 20ft if you're grappling. If your character is at least 4ft tall, they can get away with jumping 8ft; 16ft movement. That's 34ft movement total; Longstrider gives you +10ft. Creatures with 25ft base movement can still do this if they're at least 6ft tall; Rune Knight 10 makes you grow up to 3d4 inches, this can be a gamechanger for small creatures and dwarves. Alternatively, pick up the Athlete feat for 5ft running start and climbing shenanigans.
At Bard 2 you get Jack of All Trades. This boosts your initiative. You also get Song of Rest.
You go Lore Bard 3 for the next level and reach your third power spike. This grants you:
Cutting Words. Now you can use your own Inspiration die. Make it count.
Expertise. A direct grappling boost.
The spell Enlarge; since Tasha's, this spell is on the Bard's spell list! Now you're a certified Tarrasque Tackler, although your stats aren't there just yet. If your DM doesn't like that and won't let you get Enlarge, you can pick it up at Lore Bard 6 anyway; in that case you should grab Enhance Ability instead.
Lore Bard 4 will grant you an ASI and thus I highly advise picking it up, although it's not mandatory at all. If you rushed Rune Knight 6, you should consider Alert, Lucky or War Caster, latter being the better pick unless you're planning on a 2-level dip into Druid at some point. See dips further down below.
Lore Bard 5 is optional; it boosts your Bardic Inspiration to blue status by increasing the die to d8 and allowing a short rest recharge. Still likely just one die and will remain so; use it wisely.
Lore Bard 6 is only for those games where the DM doesn't like Tasha's giving Enlarge to Bards. You gain access to Enlarge and one additional spell of your choice. Decent choices include Shield, Absorb Elements and Hex.
A better alternative is a Sorceror dip for those reaction spells. See dips further below.
Now you'll go back to Rune Knight. I'll assume you already got Rune Knight 6, so let's jump to 7: You get to choose a new rune! This is your fourth power spike.
Hill Rune is half a Rage plus a Dwarf racial bonus, that recharges with a short rest. The resistances will massively help your concentration saves by nuking the DC, as well as preserve your hit points. Awesome choice and is what I'd pick up first.
Storm Rune is a third of the Alert feat and an on-demand advantage or disadvantage, once per round, using your reaction, for 10 rounds. It can affect anyone within 60ft of you and can manipulate essentially any d20 roll. Your spellcasters will love you; disadvantage on save-or-suck spells, including every time the poor target attempts a new save, is just hilarious. Oh, did I mention it recharges every short rest?
Rune Knight 8 gives you an ASI. Consider a +2 STR or a sky blue feat. You can function well even with 16 STR and you'll get one more ASI guaranteed, even up to two more if you don't dip into other classes too much.
Rune Knight 9 introduces Indomitable, a.k.a. second chance for a failed save. If you have the Lucky feat and aren't afraid to spam the luck dice this can essentially grant you highest of 4d20 on one save per day, or even better if you already had advantage on the save (that specific instace grants you highest of 6d20, respectively). That one interaction with Lucky is more than enough reason to consider the feat.
Rune Knight 10 lets you pick up your last rune which will essentially be either Hill or Storm, whichever you didn't pick up at Rune Knight 7. You'll also grow taller and gain an upgrade to essentially the only feature of Giant's Might that you don't care much about.
Rune Knight 11 is your fifth power spike, with Extra Attack 2.
Rune Knight 12 grants you an ASI.
After you got to Rune Knight 7 / Lore Bard 3 at the very least (or Lore Bard 6 if that's how you got Enlarge), you can dip at any point. Here are your options for the build's end-game:
Rune Knight 14 / Lore Bard 5 for more Indomitable, an ASI and dip one level into a third class.
Rune Knight 15 / Lore Bard 5 for more Indomitable, an ASI and Rune Knight 15 which now grants you two uses of your runes per short rest, as well as a 5th rune choice!
Rune Knight 15 / Lore Bard 4 for the same deal as above but trading your Bardic Inspiration upgrade for a dip into a third class.
Rune Knight 15 / Lore Bard 3 for keeping the awesome Rune Knight 15 boosts but trading Inspiration upgrade and an ASI for two levels to dip into other classes.
Rune Knight 13 / Lore Bard 5 for more Indomitable but trading an ASI and Rune Knight 15 for two levels to dip in other classes.
Any further combinations, as long as you have at least Rune Knight 13 / Lore Bard 3. You have plenty of good options for dips; it'll be up for you to choose what you are willing to give up for them.
Bard Spells
Avoid attack roll or save based spells, including cantrips. You'll have at best 14 CHA; that's just not good enough. In addition, concentration spells compete with Enlarge when you're fighting gargantuan ceratures. Having said that, Bard spells to consider learning are the following:
Light, cantrip. This can help if you don't have Darkvision. Cast it on a pebble and throw for a situational distraction.
Prestidigitation, cantrip. Chilling and warming objects can be useful in a survival situation and can create a heat source without light. Alternatively, light a campfire easily.
Cure Wounds, 1st. You're not the party healer but when DMs penalize pop-up healing via Healing Word, you can use this outside combat for a bit better mileage.
Feather Fall, 1st. Good for insurance but a bit too specific.
Healing Word, 1st. As useful as ever. Always nice to be able to one-up the Cleric and make the DM wonder who to focus in combat.
Heroism, 1st. Concentration. Immunity against being frightened is great.
Longstrider, 1st. Becomes gold if you can use the jump-prone tactic. A useful buff with long duration.
Enhance Ability, 2nd. Concentration. Outside of buffing allies' ability checks, it's useful for one more reason: when the party decides to use Stealth, you can cancel your armor's disadvantage.
Enlarge, 2nd. Concentration. This is what lets you grapple gargantuan creatures when combined with Giant's Might.
Heat Metal, 2nd. Concentration. This spell doesn't have a save when you cast it on armor and provides a great debuff. You can also cast it on a weapon to disarm someone. The only downside is it takes your bonus action. It also does some damage.
Silence, 2nd. Concentration. There are less than 30 spells total that don't use verbal components, across all official 5e sources, and less than 20 of those are 1st level or higher. You're already a frontliner, go grapple those mages and cast this. At best, they become useless. At worst, they escape the grapple, stand up and move 15-20 ft away from you, still being in Silence's radius. They can't even Dispel it without an ally doing it for them, since that also has a verbal component. Most spellcasters aren't gargantuan, which means you tend to be able to affort casting Silence when you need it.
Catnap, 3rd. If your allies frequently find themselves in a need of a short rest with less than an hour but more than 10 minutes to share, this can be useful. That situation is extremely rare, however.
Dispel Magic, 3rd. This is a trap. It would be good if you could upcast it. You can't, so stay far away from it.
Glyph of Warding, 3rd. This is gold if you're in a game where defending an area or structure is the most important element, you get at least a few hours to prepare, and you have enough money to afford this spell. With careful triggers you can set up a few buffs and even heals for yourself and/or your allies with zero action economy footprint in combat. Quite useless in most other circumstances.
Motivational Speech, 3rd. For those times when you are going to fight a gargantuan creature very soon and you want some sort of party-wide buff to WIS saves. Not really good but at least it's something; it's not blue because it doesn't affect you, only your allies.
The Rogue Route
The Rogue route grants you Expertise at Rogue 1 but delays Enlarge to Rogue 8. This is a much longer multiclass commitment and the delay on Enlarge is mainly the reason it's blue, as well as Sneak Attack being completely useless for both grappling and unarmed strikes. This changes drastically if you can convince your DM to let you use a finesse dagger built into your boot or something similar you can kick with that qualifies, however it does mean you're wasting a grapple/shove opportunity on an attack. The immediate Expertise you gain does mean you might end up with "free" attacks more often after you're done with your usual skill check rotation.
Rogue 1 has Expertise, your third power spike.
Rogue 2 grants Cunning Action, a luxury feature that lets you drag creatures twice as far for a bonus action, enabling all kinds of shenanigans. Blue only because you already have massive competition for your bonus action, even if you didn't pick up Shield Master.
Arcane Trickster 3 for the archetype. The spells will be mostly illusions, in addition to whatever you can get away with that grants some utility. Your spell DC will suck, don't even think about combat value until level 8.
Arcane Trickster 4 grants you an ASI. Consider a sky blue feat.
Since this multiclass sequence takes longer to finish, feel free to pick up Rune Knight 7 around between Arcane trickster 4 and 5 for your fourth power spike. I recommend Hill rune; see the Bard path for details on the runes.
Arcane Trickster 5 is Uncanny Dodge time, a decent defensive option that can cover attack damage types your Hill Rune does not.
Arcane Trickster 6 is essentially a dead level; you don't really need more Expertise in combat but the Rogue route can fill quite a few out-of-combat roles so not completely useless.
Arcane Trickster 7 grants Evasion, meaning you don't have to use your bonus action on Shield Master ever again.
Arcane Trickster 8 finally grants you Enlarge, bringing about your fifth power spike and enabling your gargantuan grappling game.
I don't recommend going for Reliable Talent. Too many dead levels without significant features and having advantage already means you'll roll under 10 only 20,25% of the time. It's nice for insurance but the opportunity cost is massive; we're talking about no Indomitable, no Extra Attack 2 and no fourth Rune. Don't do it.
So, Rune Knight 8. That's an ASI. It's your last guaranteed one, keep that in mind. By now you ideally have both gold feats and two or even three sky blue feats.
Rune Knight 9 grants you Indomitable. See the Bard path for a detailed praise of this ability.
Rune Knight 10 is the point where you pick up the Hill or Storm Rune, whichever you didn't grab at Runic Knight 7. You also grow a bit in height and get a bit better damage during Giant's Might.
Rune Knight 11 is your sixth power spike as you gain Extra Attack 2.
After you've reached Rune Knight 7 / Arcane Trickster 8, you can plan out the build's end-game. You can dip any time after that point; here are your options:
Rune Knight 12 / Arcane Trickster 8 for an ASI.
Rune Knight 11 / Arcane Trickster 8 and a one level dip into a third class.
Dip Tips
Any class not on this list is either not worth considering or you can't dip into due to the ability score array.
Barbarian, 13 STR. Two levels or none, you're here for Danger Sense. Not really worth giving up an ASI and a second Indomitable use but if you want it, you can certainly have it.
Cleric, 13 WIS. One level only. Forge Domain for Blessing of the Forge. Now, normally this is just a +1 AC but if you have Shield Master and your shield is still nonmagical, this bonus becomes +1 AC and +1 DEX save. That's much better! Peace Domain for Emboldening Bond which is a no-concentration Bless that lasts for 10 minutes, can also boost ability checks, including initiative, but only grants 1d4 once per turn and requires buddies to be within 30ft of each other. Number of uses scales with proficiency; this thing was practically made for multiclass dips. It also stacks with actual Bless and grants the Rogue route access to Healing Word.
Druid, 13 WIS. Two levels or none. Wild Companion can grant advantage to party members with the Help action. Circle of Stars grants Starry Form which can give you a Reliable Talent effect for your concentration saves! This is very good if you don't want to pick up War Caster, it's an adequate replacement but otherwise overkill.
Sorcerer, 13 CHA. One level only. Pick up Shield and Absorb Elements. Clockwork Soul has Restore Blalance, an incredibly situational die manipulation option. Divine Soul gets Favored by the Gods, a once-per-short-rest save boost of 2d4. That is pretty good, a high chance of getting a 4-6 on the roll. Consistency is king in the realm of RNG, this is gold.
Warlock, 13 CHA. One level only. Pact of the Talisman can grant you an additional 1d4 to your ability check whenever you would fail; uses scale with proficiency. Gain access to Hex. Celestial Patron grants Healing Light for some utility. Invocation can be Devil's Sight for that magical Darkvision or Fiendish Vigor to have your entire party start every battle with 1d4+4 more health. A solid pick with more party utility focus than Sorcerer.
Paladin, 13 STR and 13 CHA. Two levels or none. Smite, Lay on Hands with 10 hit point pool and a second Fighting Style. If you feel your party needs damage and you want to fill that need, this is the dip for you. Smite lets you do significant burst damage with just one attack which doesn't hurt your action economy too much, and you can pick up Blind Fighting, Dueling (if your DM allows that to work with unarmed strikes) or Defense.