Lab of Legends - Runeterra Labs

This is a guide for the Legends of Runeterra single-player PvE lab, "Lab of Legends".

Let us start by saying this new lab is a fantastic experience and, if you haven't played it at all yet, you might want to play a run or 2 "blind" just so you fully experience it. If you're struggling with some of the specifics or just want to make sure even your first run is fully optimized, though, we're here for you.

The Rules

Quote From Lab Description
Choose a champion and challenge a gauntlet of increasingly powerful foes in this single player adventure!


  • The format is similar to Hearthstone’s “Dungeon Run” single player content
  • You will start each run with a choice between 10 different Champions, each with their own premade deck
  • After you select your hero, you’ll fight a series of matches against 9 AI opponents.
    • Every 3rd fight is a "Boss Encounter" against an enemy champion
    • Your Nexus health carries over between matches and is only refilled after Boss Encounters
  • Between matches, you’ll be able to upgrade your deck with new cards, passive abilities, and “items that power up cards in unique ways”
  • The first time you successfully complete a run with a particular Champion, you’ll be awarded a unique player icon for that Champion


Here's some great advice from Lady Merlin on from her reddit post (used with permission).

Quote From Lady Merlin

  1. Don't Be Afraid to Reroll your Starting Passive Power - Abandoning a run to make a new run takes about 5 seconds while a Perfect 9 Win Run takes between 30 min to an hour to achieve. A good starting passive power makes your whole run easier.

  2. Healing is Premium - Since you don’t regenerate health between matches normally, drafting Healing cards can save a run. If at all possible, stall and make sure you end each match with as much HP as you can afford to (some opponents you shouldn’t stall - see below). Note that Lifesteal effects affect your Main Health total only if your opponent is alive when they hit. While your health in game will visually change in-game if Lifesteal champions or followers hit the opposing Nexus after it’s gone to 0, they won’t count for your next match.

  3. Stack Buffs - Items are permanent buffs that affect a card - and all copies of the card you have. It’s usually best to continually pick the same Champion, Minions, and Spells that already have Items on them, as each time you draft them you add additional copies to your deck that all are permanently buffed. Note: Champion Spells are not the same as Spells without their name and won’t share buffs between each other.

  4. Start with Aphelios - His deck has built-in Lifesteal (Severum) and you benefit a lot from drafting Aphelios over and over, adding more Items to him (like a true ADC in League of Legends, he is so much better at that 3-4 Item breakpoint). Use this run to learn the ins and outs of your opponents and how the drafting process goes.

  5. Your Main Opponent is Not the AI, but Your Own Deck - achieving 9 wins in a row requires you to make sure you have a solid amount of early game cards (or you will draw all your expensive cards at least one game out of 9). If you draft a lot of buff spells, make sure you have a commensurate amount of minions to buff.

  6. Take it easy! As a vs. AI format, there is no Turn Timer. You have as much time as you like calculating all the moves you need to make each turn.

  7. You Don't Have to Stick with your Starting Champion Some Champions have a harder time in this format than others. Sometimes it makes more sense going all-in on your Support Champions instead of your Starting ones - especially since so many of the Items are combat oriented. Ex: During my Heimer run I drafted an early Vi who was much better with my Evolution Passive and so I focused on drafting more copies of her + Items (Twin Shadows, which allows you to level up the same turn you play her + benefit from her Level Up ability).

(Mana) Cost is King

It cannot be overstated how important early game tempo is in this game mode. Unlike normal ladder games where you can afford to build a slower midgame-oriented deck, you really need to establish early board to minimize Nexus damage and try to end the matches sooner rather than later to succeed against all 9 AI opponents. This means that items that reduce the mana cost of their cards and abilities that either give you additional mana or make certain cards cheaper are especially valuable. It also means that early game units are critical -- sometimes it's worth picking an Omen Hawk or a Mountain Goat that has a meaningless item attached just because it means adding additional copies of that card into your deck. Units that cost more than 5 mana are almost always bad choices -- you want to be ending these games around Round 5, not just starting to stabilize.

If you've had a run that felt particularly disastrous, spend a few minutes looking at your Run Summary. How many cards did your deck include for playing Rounds 1 - 3? How many were limited to Rounds 5+? It's much more difficult to make a balanced curve in draft formats than in constructed formats, but you still need to keep your early game in mind when making your card choices.

Starting a New Run

You will start your run by choosing a difficult tier and one of the 10 possible Champions for this lab. These champions are:

  • Aphelios (Targon)
    • Prioritize powers that either reduce the cost of your moon weapons or give you additional mana
  • Heimerdinger (P&Z)
    • Prioritize powers that give additional mana and healing effects
  • Lulu (Ionia)
    • Prioritize upgrades that put additional units on board and challenger units 
  • Lucian (Demacia)
    • Prioritize upgrades that put additional units on board and Rally effects
  • Riven (Noxus)
    • Prioritize Rally effects and card draw
  • Braum (Frejlord)
    • Prioritize ally buffs and card draw
  • Miss Fortune (Bilgewater)
    • Prioritize Rally effects and upgrades that put additional units on board
  • Hecarim (Shadow Isles)
    • Prioritize ephemeral synergies and healing
  • Azir (Shurima)
    • Prioritize upgrades that put additional units on board and Rally effects
  • Taliyah (Shurima)
    • Prioritize healing effects and card draw

Selecting a Champion will start you with a fixed deck that includes 2 copies of said Champion along with 2 copies of 8 other cards from that region intended to synergize with that Champion (18 cards total).

Next, you'll chose your 1st global passive "Power". 3 randomly-picked options will appear, and you will have to chose 1. If you don't like your options here, you can use one of your 3 rerolls; however as Lady Merlin pointed out it makes more practical sense to just retire your run and start a new one. Each choice will have a quality (Common / Rare / Epic) corresponding to their rarity and overall power. Don't just snap pick the rarest option, though -- each merits consideration about how it will synergize with your intended strategy.

Turning a "Support" Champion into a Carry

If you're having trouble with any particular champion -- slower champs like Heimerdinger, Braum, Hecarim, and Taliyah in particular -- try this strategy:

  1. Start a new run with the problem champion
  2. Beat Spiders
  3. After beating Spiders, you'll be given your choice of a Support Champion
    • Look for an early-game support champ that provides tempo and costs 1-4 mana.
    • If you don't get offered one: re-roll up to two times
    • If you're on the last reroll and still don't see a good tempo champ: retire the run immediately and go back to #1
  4. When you get offered Champ Item upgrades, prioritize this tempo Champion. Even if the items aren't especially synergistic, you want to pick the tempo Champion as it will put additional copies in your deck
    • You can deviate once if there's a exceptionally synergistic item for the original champion, but the goal behind this approach is to try to maximize your chances of drawing into your tempo Champion and minimizing the role of the original Champion.

Good examples of tempo champs include:

The logic behind this approach harkens back that golden mantra, "(Mana) Cost is King". Champions like Heimerdinger, Braum, Hecarim, and Taliyah are remarkably slow: not only are their mana costs large, but they also difficult to level up and/or very dependent on other cards to provide value. For this game mode -- and especially for Foundry, Guard Bots, and Viktor -- you want to be applying pressure and turning the proverbial screws around Rounds 5-7, not just beginning to stabilize. That's why we want to refocus the run towards an alternative champion who's more impactful in the early game. 


There are four difficulty settings: Normal, Hard, Heroic, and Legendary.

  1. Normal: This is the default difficult setting
  2. Hard: All opponents have +5 Nexus health; a few enemy cards have items attached
  3. Heroic: Opponents start the game with a particular "Reinforcement" unit already in play
  4. Legendary: Opponents start the game with full spell mana and have even more cards with items attached

The difficulties are champion-locked -- i.e., if you haven't successfully completed a "Normal" run with a particular Champion, that Champion will be unavailable if you change the difficulty to "Hard".

Successfully completing a run with a particular Champion on Normal will award a corresponding player icon for that Champion. There are no rewards yet for successfully completing runs in the higher difficulties.


After you select your difficulty, starting champion, and 1st passive power, you'll face the following 9 opponents. Each run always faces the same opponents in the exact same order with the same abilities and deck.

1. Spiders

  • Nexus Health: 10 for Normal difficulty; 15 for Hard difficulty and greater.
  • Ability: Spiders Everywhere: Round Start: Create a Fleeting Spiderling in your hand.
  • Reinforcement: Starts with a Pesky Specter for Heroic and greater.
  • Cards to Watch Out For: Vile Feast, Frenzied Skitterer (especially as a 2nd play in Round 4).
  • Notes: This should be a "freebie" match to get you started; just try to minimize your health loss.
  • Reward:
    • Support Champion (2 copies of a new champion plus 2 copies of 2 supporting cards; 6 cards total)

2. Mistwraiths

  • Nexus Health: 10 for Normal difficulty; 15 for Hard difficulty and greater. 
  • Ability: Dead Rise: When an ally Mistwraith dies, create a copy in deck.
  • Reinforcement: Starts with a Barkbeast for Heroic and greater.
  • Cards to Watch Out For: Vengeance, Risen Mists.
  • Notes: Don't be too eager to kill of the Mistwraiths -- it just makes the AI that much more likely to top-deck another one, and their attack will grow very quickly.
  • Reward:
    • Champion Item (chose an item plus which champion it goes on; one additional copy of that champ)
    • New Card Reinforcements (2 copies of a new spell; no items)

3. Thresh (Boss)

  • Nexus Health: 10 for Normal difficulty; 15 for Hard difficulty and greater 
  • Ability: Damnation: Start with Vaults of Helia. When Thresh levels up, create 3 Shadow Isles champions in your deck.3. 
  • Reinforcement: Starts with a Warden's Prey for Heroic and greater (immediately dies to Vaults and pulls a random 2-drop
  • Cards to Watch Out For: Vengeance, The Box, Thresh, The Ruination
  • Notes: Prioritize killing off the most expensive enemy unit every round to deny Vault value -- ideally doing a full clear. Also watch out for Thresh: the AI starts the match with 1 copy in hand and he can level fairly easily.
  • Rewards:
    • 2nd Passive Power
    • New Spell Reinforcements (2 copies of a new spell; no item)
    • Health reset

4. Hunters

  • Nexus Health: 20 for Normal difficulty; 25 for Hard difficulty and greater.
  • Ability: Frozen Earth:Round Start: Give the Weakest enemy Vulnerable this round.
  • Reinforcement: Starts with a Avarosan Sentry for Heroic and greater.
  • Cards to Watch Out For: Culling Strike, Take Heart, Alpha Wildclaw into your Vulnerable units.
  • Rewards:
    • New Follower Reinforcements (2 copies of a new follower with a item)
    • Existing Card Reinforcements (add an item to an card already in your deck plus 1 additional copy)

5. Scars

  • Nexus Health: 20 for Normal difficulty; 25 for Hard difficulty and greater.
  • Ability: Proving Grounds: Start with The Scargrounds.
  • Reinforcement: Starts with a Unscarred Reaver for Heroic and greater.
  • Notes: The trick here is to find the balance of not giving enemy units cheap Scarground pings but not being too passive either. 
  • Cards to Watch Out For: Elixir of Iron, Bloodsworn Pledge, Avalanche, Tarkaz the Tribeless, Scarmother Vrynna.
  • Rewards:
    • New Spell Reinforcements (2 copies of a new spell with an item)
    • Existing Card Reinforcements (add an item to a card already in your deck plus 1 additional copy)

6. Sejuani (Boss)

  • Nexus Health: 20 for Normal difficulty; 25 for Hard difficulty and greater.
  • Ability: Endure: When you summon an ally, grant it +1/+1.
  • Reinforcement: Starts with a Wyrding Stones for Heroic and greater.
  • Cards to Watch Out For: Flash Freeze, Caught in the Cold, Fury of the North.
  • Rewards:
    • 3rd Passive Power
    • Champion Item (chose an item plus which champion it goes on; one additional copy of that champ)
    • Health Reset

7. Foundry

  • Nexus Health: 30 for Normal difficulty; 35 for Hard difficulty and greater.
  • Ability: Working Overtime: Start with Hexcore Foundry. Your cards cost 1 less.
  • Reinforcement: Starts with a Professor von Yipp for Heroic and greater.
  • Notes: This is a harder matchup then you might expect. Foundry likes to play grindy attrition games; they will summon hordes of chump blockers and let their Poison Puffcaps and burn spells do their work. Even if they can't directly knock you out, they'll try to soften you up enough that Guard Bots and Viktor can finish the job. Mulligan hard for cards with low mana cost and look for opportunities to punch through their chump blocks (Overwhelm, Elusive, Rally, etc). 
  • Cards to Watch Out For: Mystic Shot, Get Excited!, Hextech Transmogulator, Shady Character.
  • Rewards:
    • Existing Card Reinforcements (add an item to an card already in your deck plus 1 additional copy)

8. Guard Bots

  • Nexus Health: 30 for Normal difficulty; 35 for Hard difficulty and greater.
  • Ability: Iterative Enhancements: Round start: summon a turret.
  • Reinforcement: Starts with a Heimerdinger for Heroic and greater.
  • Notes: This is a game where you cannot win the long game -- a free T-Hex every round is too brutal to keep up with. Look for ways to end the game before that, and always plan ahead for which turret the AI will summon next round.
  • Cards to Watch Out For: Trueshot Barrage, Thermogenic Beam, Unstable Voltician, Plaza Guardian.
  • Rewards:
    • Reinforcements (add an item to an card already in your deck plus 1 additional copy)

9. Viktor (Boss)

  • Nexus Health: 30 for Normal difficulty; 35 for Hard difficulty and greater.
  • Ability: Beyond the Flesh: Allies have +1|+1 for each keyword they have.
  • Reinforcement: Starts with a Ballistic Bot for Heroic and greater.
  • Notes: For all the gimmicks of prior matches, this fight is surprisingly straight forward. The one card to look out for is Viktor: since his Hex Core Upgrade gives him a new keyword, he will net +2|+1 every time he casts it. This gives him a lot of snowball potential.
  • Cards to Watch Out For: Viktor, Mechanized Mimic, Death Ray - Mk 1
  • Rewards:
    • If its you're first time completing with this champion, you'll receive the award icon!


There are 3 types of upgrades: cards, Powers, and Items. The cards just add copies of the designated card to your deck. Powers provide a powerful passive ability; you start the game with one and get to choose an additional Power after each Boss Encounter. The Items are the most complicated and most interesting --  they will all copies of a particular card (e.g., give it a keyword or reduce its cost). When you pick an item, you also receive an additional copy of that card to your deck. It usually pays to "stack" Items on a limited number of cards. 

Lady Merlin has provided an list of Powers and Items and also designated particular options as generally superior; those options are designated by **asterisks**.


Common Powers

  • Dragon's Rage: When you summon a unit, grant it Fury. It is a Dragon
  • Empty Mind:  When your hand is empty, draw 1.
  • Enfeebling Strike: When you damage an enemy, reduce its Power by the damage dealt
  • Fast Deal: Round Start: Draw 1 and give it Fleeting. When you discard a card, shuffle a copy into your deck.
  • Flexible Game Plan: Start of Game: Draw 1
  • Higher Education: When you draw a card, give allies +1|+0 this round.
  • Immortality: Start of Game: Heal your Nexus 10
  • **Sorcery: Round Start: Refill your spell mana**
  • Wild Inspiration: Your created spells cost 1 less

Rare Powers

  • Best Defense: Allies have "Attack: Raise my Health to match my Power"
  • Can't Stop; Won't Stop: Allied buffs (except Barrier) are permanent
  • **Domination: Round start: Rally**
  • **Grit: Allies have "Attack: Raise my Power to match my Health."
  • **Manaflow: Start of Game: Get an empty mana gem**
  • **Out the Gates: Start of the Game: Summon a 2 cost unit from your deck.
  • Spellslinger: Your spells cost 1 less

Epic Powers

  • **Black Market Discount: Round End: Reduce the cost of your most expensive card in your hand by 1**
  • **Evolution: Allies have +1|+1 for each keyword they have**
    • Really fantastic with Champions who were given Items that give additional keywords**
  • **Lil' Buddies: Round Start: Summon a random 1 cost Poro**
  • **Nature's Revenge: When you gain attack token, summon a Sapling**
  • Share the Bounty: When you target an ally with a single-target spell, copy it on your weakest ally.
  • Trifarian Might: When you play a unit with 5 or more Power, it strikes the Weakest enemy.
  • Yipp's Genius: When you summon a 1 cost unit, grant it +2|+2


Items vary a little based on whether the target card is a unit, spell, or landmark.

Items for Units

  • **Banshee's Veil: Spellshield**
  • The Brutalizer: Overwhelm
  • Chain Vest: Tough
  • Doran's Blade: +1|+1
  • Giant's Belt: +0/+2
  • Locket of the Solari: Barrier
  • Phantom Dancer: Quick Attack
  • Philosopher's Stone: When I'm summoned, draw 1
  • Pickaxe: +2|+0
  • Sterak's Gage: Fury
  • Ancient Coin: -1 Cost
  • **Archangel's Staff: When I'm summoned, refill your mana equal to my cost**
  • **Avarice Blade: Attack: Nab 1**
  • Frozen Mallet: +4|+4, costs 2 more
    • Almost always a horrible choice -- low mana costs are very important
  • **Phage: +2|+2**
  • Spirit of the Spectral Wraith: +3/+3, but Ephemeral
  • Twin Shadows: When I'm summoned, summon an Ephemeral copy of me
  • Warmog's Armor: Regeneration
  • Golden Spatula: "It must do something..."
    • It actually does multiple things; refer to the corresponding section below for details
  • Hunter's Machete: Scout
  • **Lich Bane: When you cast a spell, grant me +1|+1**
  • **Ninja Tabi: Elusive**
  • **Nomad's Medallion: -2 cost**
  • Spirit Stone: When I'm summoned, create a Fleeting copy of me in hand
    • If given to a Champion, that copy will instantly become their signature spell
  • Sterak's Fervor: Last Breath: Rally

Items for Spells 

  • Elixir of Skill: When cast, draw 1.
  • Health Potion: When cast, heal your Nexus 3
  • Mana Potion: -1 cost
  • Poro Snax: When cast, summon a random 1 cost Poro.
  • Elixir of Sorcery: When cast, cast me again onto the same targets.
  • **Tear of the Goddess: -2 cost**
  • Wooglet's Witchcap: When cast, shuffle 2 copies of me into your deck. They cost 1.
  • **Chalice of Harmony: -3 Cost**
  • Spellbinder: When you cast a spell, reduce my cost by 1

Items linked to spells will not apply to Champion's signature spells (e.g., if you give Take Heart the Chalice of Harmony, Braum's Take Heart will still cost the full 3 mana).

Items for Landmarks:

  • Zz'Rot Portal: When I'm summoned, summon a copy of me.

Golden Spatula Item

The Golden Spatula is a new item added in the Patch 2.5 "upgrade" which will provide random benefits every time the unit is played. Specifically:

  • It will randomize stats. The final attack + health total will always be 2-3 points higher than the original, however it is possible for one attribute to be lower. (Think like how Slotbot rearranges its stats at the start of every round, except this effect only occurs when summoned)
  • It adds a new keyword.
  • Both the stat randomization and new keyword are assigned when summoned -- in other words, you don't know what you'll get while it's in hand
  • Any existing keywords or abilities are preserved.

Reddit user shared these results when used with the 2|3 Aspiring Chronomancer:

Quote From u/Physical-Woodpecker3

My run is over now, but the item set the 2/3 to

  • 3/4 Fearsome
  • 4/3 Quick Attack
  • 2/5 Challenger
  • 5/2 Spellshield (Its health was red as if it received damage)
  • 2/5 Quick Attack
  • 4/3 Regen
  • 5/3 Spellshield
  • 4/3 Elusive
  • 2/5 Overwhelm
  • 3/4 Scout
  • 5/2 Quick Attack

Do note that the card's buff reads "Set to X/X" not "+X/+X".

Works on summon so playing from hand is not required.

Rewards Icons

If you beat all 9 opponents with a single deck, you will see a notification that you have earned an icon for the corresponding champion. To collect the icon, go to the "Home" screen and click the "Loot" button in the bottom right of the screen.

To change your current Player Icon to the new icon, go again to the "Home" and click on your current icon (the circular image near the top-left corner) to bring up your status page. From here, click on your icon again and you will receive a popup with all the icons you have currently earned. Scroll down until you see the new icon you want to use -- all the lab rewards will say "Legends Lab, (month and year of acquisition)" -- and select it.

When We've Seen Lab of Legends

Started Ended
Wednesday, February 03, 2021 Wednesday, February 17, 2021
Wednesday, February 17, 2021 Wednesday, March 03, 2021
Wednesday, March 03, 2021 Wednesday, March 17, 2021
Wednesday, March 17, 2021 Wednesday, March 31, 2021
Wednesday, March 31, 2021 Wednesday, April 14, 2021


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