Exploration Guide – Last Fortress: Underground

Last updated: 07.14.2024 ☣ Game version: 1.368.001

Exploration is a PvE game mode in Last Fortress where you fight against enemies whose difficulty level rises with each battle. 

In the Exploration Mode, you go through various stations, each presenting battles against progressively tougher enemies. The deeper you go, the more challenging the battles become, requiring adjustments to your lineup and gear.

Exploration is pretty important to push because of the m-coins and EXP hourly income it provides. Both let you level up your heroes and upgrade the hero statues for bonus stats.

After the War Room introduction in Version 1.361, Exploration became the only free (consistent) source of the War Room resources: Link EXP, Link Coin, and Link Chips. All these are needed to upgrade your heroes past level 100.

You could also get Minutemen heroes and some hero selection cards for certain Exploration levels, but I do not know if it is still in the game. Let me know if it is true or not.

Exploration Basics

Access

You get access to Exploration pretty early in the game after digging down and discovering the Subway Entrance in your base.

After that, you will be able to access Exploration by either selecting the entrance and pressing “Explore” or (the normal way) by pressing “Battle” in the bottom right corner and choosing “Explore” on the left.

There, you will see two “tappable” things – a chest on the left and a “Challenge” button on the right.

If you tap the chest, you will see your current accumulated rewards and m-coin and EXP income rate. And by pressing the “Challenge” button, you will see the rewards for defeating the next enemy lineup and the enemy lineup itself.

Rewards

The first thing you need to know is that the rewards do not go directly to your inventory every hour. They accumulate in this Exploration chest, and you need to collect them manually by going to this chest and pressing “Claim.”

The initial collection limit is 10 hours, so it won’t accumulate further than 10 hours until you claim the rewards. You can increase it to 25 hours by getting your VIP level higher.

The rate of EXP and m-coins is written as follows: 

+BASE-RATE/min (+UPGRADE-RATE/min)

(+VIP-RATE/min; VIP buff activated)

• BASE-RATE is the raw Exploration rate you get from the number of levels you have beaten.
  • The m-coin time you use from your inventory applies only to this rate, ignoring any bonuses.
• UPGRADE-RATE is the bonus you get from various upgrades (Solari heroes, Premium Pass, Policy Card).
• VIP-RATE is the bonus from your VIP level.

And the sum of all these is your total rate of EXP and m-coins.

Note: all bonuses apply to the BASE-RATE value.

The income rate of EXP and m-coins increases every five stations you beat (10-5, 10-10, 11-5, 11-10, etc.). It is +100 for EXP and +5 for m-coins.

As for Link EXP, Coins, and Chips, their rate is not displayed for now. I have been told that, at the max Exploration level, it is 128 per hour for Link EXP, 60 per hour for Link Coins, and 1 per 4 hours for Link Chips.

How to increase Exploration rewards

There are four ways of increasing the amount of EXP and m-coins you get from Exploration:

1. Progressing in Exploration – this one is straightforward. The further you get, the higher your base rate becomes, and the bigger the bonus from other sources.
2. Upgrading Solari skills – some of the Solari heroes have skills that provide Exporation reward bonuses. You can get +60% to Exploration rewards from these skills:
   1. Harrison’s, Emma’s, and Bacchus’ third skills are all called “Commemorative Coins obtained from Explorations.” Each gives up to a 10% increase in Exploration rewards. So that’s +30%. 
   2. Wolowitz’s second skill, “Exploration buff,” provides up to a 30% increase in Exploration rewards.
3. Getting a 5-star policy card “Directional Exploration.” It provides a +15% m-coins-only Exploration buff, which can be increased to +23% by upgrading this card to the maximum. BUT, it has a negative effect too – you won’t get any EXP from Exploration when you are offline. So, I’d say this card is not worth equipping.
4. Upgrading your VIP level. The higher your VIP level, the higher the Exploration Collection buff. The maximum is +69% to rewards.
5. Buying premium. It gives a +50% bonus to Exploration EXP and m-coins output. I do not recommend anyone to invest in this game, but if you are considering doing it, the Premium Pass is one of the few things actually worth getting in this game.

The maximum exploration level is 100, corresponding to 50-10 stations. That means the maximum base rate of EXP is 16,500/min and 750/h for m-coins.

The maximum bonus you can get (without the policy card) is +179%. And when applied, your highest EXP rate would be 46,035/min (2,76m/min) and 2,092.5/h for m-coins.

Oh, and for each defeated enemy lineup, you will get a one-time reward. For all but -5 and -10 levels, you will get one Raw Material Chest, 50 recruitment points, 50 m-coins, and a certain amount of EXP that increases by 1,000 with every beaten station.

For every station battle that ends with -5, you get 50 more recruitment points, and for every station that ends with -10, you get 450 more.

Battles

After pressing the “Challenge” button, you will see what enemy lineup you will fight and the one-time reward for winning. You can also press this white button in the upper right corner to see the three winning lineups of other players: the one that got the first kill, the most recent one, and one from your alliance (if such exists).

The button:

Winning lineups example:

You can also replay their battles to see how they went. But, unfortunately, you won’t see what gear these lineups are running, so what worked for those lineups won’t necessarily work for you.

After pressing the “Fight” button, you will see the usual fighting screen, where you can choose the heroes to fight.

A couple of things to note:

• You cannot choose any APCs
• You cannot choose any Beasts
• You cannot skip the battle
• Troop level and upgrades do not affect the battle
• VIP level 3 unlocks the x4 battle speed for Exploration

Hence, everything will depend on your heroes’ levels, quality, gear, ultimate weapons (UW), and positioning. 

After starting the battle, you can press the Pause button in the upper right corner.

There, you have three options:

• X – Leave: straight up exit the Exploration fight. You tried everything you could, you see that the battle is not going your way, so you can end it prematurely and save some time.
• ↻ – Restart: go back to choosing heroes. If you see that the current configuration is not working or you made a mistake, you can restart the fight.
  • This button will be your friend during the hardest fights in Exploration. Sometimes, you would need to be patient and hit that restart button a lot until you get the right RNG to win.
• ▶ – Continue: just continue the fight.

Solari battle bonuses

There are Solari hero skills that specifically strengthen your heroes during the Exploration fights. You might consider leveling them up if you struggle to progress in Exploration and have no other way of powering up your heroes for now.

These skills are as follows:

• Bonnie’s 4th skill – DEF +1/2/3/4/5% during Exploration
• Brady’s 3rd skill – ATK +1/2/3/4/5% during Exploration
• Fernando’s 2nd skill – ATK +1/2/3/4/5% during Exploration
• Fernando’s 4th skill – DEF during Exploration +1/2/3/4/5%
• Lafite Marceau’s 4th skill – DEF during Exploration +1/2/3/4/5%
• Bacchus’ 2nd skill – ATK +1/2/3/4/5% during Exploration
• Lori’s 3rd skill – ATK +1/2/3/4/5% during Exploration
• Maurer’s 3rd skill – DEF +1/2/3/4/5% during Exploration
• Pamela’s 3rd skill – DEF +1/2/3/4/5% during Exploration

If you max these out, you will get +25% to DEF and +20% to ATK during Exploration.

Focus on +ATK skills, as DEF will not matter as much because of how fast the enemy lineups scale up in power.

Lineup Strategy

Your general strategy is always to kill the enemy’s back-row heroes as fast as possible. However, the means you will use will depend on your current season and the heroes you have. So, let’s break the overall strategy into two main periods: S0-5 and S5+.

I will not mention P2W stuff like Wreakers heroes or special gear you can only buy. If you have that, use it. Any special gear is better than what you can get for free. 

Some of the general progression tips to consider:

• Save up faction cards for S5 when Heytex is introduced to try and get as many of him as you can.
• Focus on one main lineup first. Level up your most evolved damage dealers to level 100; tanks can stay level 70 until you do that.
• Low AGI strat is not necessary for all battles. Only those enemy lineups that have Kelly or Rebecca might force you to do it.
• Do not level up your epic gear past level 15 till you get Resolute and Super Core gear.
• After getting the Resolute gear, level up the one for Heytex first.
• For upgrading your gear to Master (red) level:
  • Save the pickaxes from the Ruins Adventure event till you have at least 250. But the more you save up, the higher the chance of getting three journals and three suits to get the Gear Modifier.
  • Save Hunter’s Ammo from the Zombie Annihilation event to exchange 1,000 for a Gear Modifier.
• Alliance Mercenaries can help you get better heroes, but I am late in the seasons, so I didn’t get this feature. Here’s a good video explanation: Alliance Mercenaries Guide.
• In Exploration, a higher LUK stat is important until the level gap between you and the enemy heroes exceeds 25. After that, you will no longer be able to outspeed the enemy, so you will need to rely on Casino’s skill and Heytex’s burst damage.
• Policy Cards
  • It appears that hero damage Policy Cards do not affect the Exploration lineup. I checked the CP before, and after adding a +INT policy card, and the lineup CP didn’t change. But correct me here if I am wrong. Maybe it just takes some time to update. If this works though, you would be having better chances of getting through stations in Dimensions.
• Research
  • War Preparations branch
    • Faction Enhancement – provides overall stat enhancement.
    • Enhanced Archers – these upgrades are supposed to improve Archer heroes as well. Heytex is an Archer, so this should improve him, too.
    • Enhanced Defenders\Commandos – the next priority.
  • Power Up branch
    • Attack & Defense
    • Attack & Defense (Master Level)
      • Soldier Rally – will not influence Exploration, as troops are not counted for in Exploration. 

Seasons 0-5

Heroes

• S0:
  • The Kelly + Rebecca combo is the easiest and most effective way to clear Exploration during the first seasons. Both heroes are quite easy to max out in 2-3 seasons. 
  • As for your other heroes, use what you have the most upgraded at this point. It is great if you can get the 4 faction heroes buff or 3+2 buff.
  • Other back-row attackers you might use are Marlene, Blanche, Laurel, and Kin.
    • Marlene – not as focused as Kelly or Rebecca, as the damage is split between two back-row heroes. But, with the recently introduced ultimate weapons, she is slightly better than before. She is used with Heytex later on to boost his already high TAC DMG.
    • Blanche – very good single-hero damage, but random.
    • Laurel – back-row damage, but dispersed.
    • Kin – hits randomly, damage is not that high. But he is very easy to max out early on in the game, so he might be your third damage dealer for quite some time.
• S1:
  • Roger – not very helpful during the Exploration. If you have upgraded him decently, you can use him as a secondary tank for a bit more damage.
  • Galande – decent combo with Kelly and Rebecca to finish off enemy back-row heroes. Just make sure he attacks after either Kelly or Rebecca so as not to waste the potential damage from those two.
• S2:
  • Elaine and Ricardo – good heroes overall, but not that good for Exploration. 
• S3:
  • Mira – good hero to use as a healer tank. She is used often in later seasons, so it is a good option for Exploration as she provides decent survivability. 
  • Penny – a worse option than Mira. She is not used that often later on, so I would not focus on her.
• S4:
  • Buccaneer – used later on in Exploration in combination with Casino as he “turns off” one enemy damage dealer for one turn.
  • Titan – rarely used. 

Gear

• S0: Reaper for STR damage dealers (like Kelly), Hurricane for INT damage dealers (like Rebecca), and the corresponding Castle versions for INT and STR tanks. Very simple.
• S1:
  • Apocalypse – do not focus on getting this. If you get this set, put it on Kelly and other damage dealers. It is inconsistent because you can’t guarantee the critical hit, but you can get lucky and push through with lucky crits.
  • Death – Galande might benefit from this one. That’s it.
• S2:
  • Tough Wall – I think this one is better for tanks than Castle because you get a consistent buff instead of a chance to block.
  • Heal – can be decent on Mira and secondary tanks with healing (like Jessie).
• S3:
  • Resolute – replace all your other gear on your damage dealers with this. Here’s when you can start upgrading epic Resolute gear past level 15. 
  • Alpha Bless – it is good to have this on at least one tank.
• S4:
  • Mental Control – partially removes the need for low AGI heroes. Put this on one of your tougher tanks and put this tank in position five.
  • Self-Healing – not used a lot. Had this tested on Titan way later in the seasons, just for fun.

Positioning

• You want your Kelly, Rebecca, or any other back-row damage dealers in positions 3, 4, and 5. 
• After you get Mental Control, you can put the tank wearing this set in position 5. Position one would still be your second tank. This opens up the opportunity to put another damage dealer in position 2.
• You can play 1 tank and 4 damage dealers. In this case, your fourth damage dealer would be in position 1 or 2.
• You can also play 2 tanks, 2 damage dealers, and 1 support. In this case, your support can go in either 3 or 5, depending on when you want that support to use their skill.

Seasons 5-8

As you conquer more and more stations in Exploration, you will see that after reaching level 100, the enemy heroes’ levels do not stop there. They will progress far beyond level 100, making the stat difference pretty big. The level difference on 45-3:

Heroes

• Heytex 103 – your main damage dealer until the end of time (or version 1.367) or until they introduce someone even more broken.
• Victoria – can be used with Ricardo and Casino. The main thing here is for Ricardo to use his skill before Victoria so that the damage from Victoria transfers to all enemy heroes. For some shields, Victoria and one other tank should wear Alpha Bless gear.
  • It is also important that Victoria is not the lowest AGI hero, as Kelly will target her and remove the shield.
  • You might need to restart the fight a couple of times, as Ricardo’s skill effect is not guaranteed to affect both front-row heroes, so Victoria can hit the unaffected one, usually rendering the fight unwinnable.
• Buri – a very decent tank. But he is used less often once you get to stations 40+.
• Casino – he will be your main support-tank for a long time. His skill plays a key role in clearing Exploration stations as it postpones the skill usage by the enemy, allowing your heroes to use theirs first.

Gear

• Super Core – a must-have on one of the heroes (usually Casino, if you do not have his p2w gear). Allows your heroes to use their skills much sooner.
• Ripper – I’ve seen it being used on Chu. Her normal attack hits multiple heroes, so higher stats increase her attack damage.

Positioning

• Casino is usually position 1 to use his skill as early as possible.
• Position 2 is either Heytex – allows him to use his skill much sooner or your second tank or some other damage dealer.
• You’d want Heytex in position 2 if the enemy lineup has a lot of back-row damage, like Laurel + Benson or Laurel + Marlene.
• Position 3 Heytex often allows him to use his skill at least twice.

Late-game Lineup Variations

Based on what heroes you have upgraded, you might have different combinations. However, they should all have Heytex at their core.

These are just some examples of decent lineup variations. Feel free to experiment, as everyone has their own set of heroes and gear available at a given moment.

Mixed

All mixed lineups have the Casino + Heytex combination. Casino delays the enemy skill usage, and Heytex is the main damage dealer.

• Lineup 1:
  • Buri – decent damage mitigation.
  • Marlene – with her epic UW, gives a buff to the TAC attacks of Heytex and Elaine.
• Lineup 2:
  • Roland – his maxed UW gives a 30% chance to stun the enemy’s from row hero.
  • Galande – should attack after Heytex and\or Laurel to make sure the final blow is delivered by him.
• Lineup 3:
  • Ricardo – should attack before your damage dealers to maximize the damage.
  • This one has the 3+2 faction bonus.
• Lineup 4:
  • Ricardo – should attack before Heytex, Victoria, and Blanche because otherwise, this combination will not work well. Ideally, he has the Alpha Bless set for more Victoria shields.
  • Blanche – can be swapped for Buccaneer or Quinn. For the latter, it is recommended for Quinn to have her maxed master UW to reduce the enemy’s DEF.
  • Victoria – make sure she is wearing Alpha Blessing for extra shield.
  • This lineup worked really well for me at stations 45+.
• Lineup 5:
  • Kinda meh. Victoria is not that good without Ricardo.

Wildlings

• Lineup 1:
  • Marlene – epic UW boosts TAC damage from Heytex and Elaine. 
  • Eva – can be replaced by Harman. Pretty weak in this spot if not wearing Resolute.
• Lineup 2:
  • Ada – provides decent survivability if you have her upgraded.
• Lineup 3:
  • This one is the most standard one.

Vindicators

Chu position 3 + Enrique position 2 is also a decent combo you can incorporate in Exploration. It is important for Chu to fire her skill before Enrique. That way, when Enrique uses his skill, he will replenish quite a lot of health, which will allow him to tank for longer.

• Lineup 1:
  • This lineup is a very standard one. I have been using it for quite a while.
  • Ricardo should use his skill before your damage dealers.
  • Heytex should ideally kill at least 1 back-row hero with his first skill usage.
  • Buccaneer turns off another back-row hero.
  • Blanche should ideally kill one back-row hero with the first skill usage. Upgrade her epic UW for more damage.
• Lineup 2:
  • This one is very similar to Lineup 1. Enrique gives a bit more survivability, and his UW gives everyone a decent Crit Rate bonus. If you fail with this lineup, you might want to try again, as crits can do their job from a second or third attempt.

Watchers

In each of these, Victoria can be replaced with Kelly.

• Lineup 1:
  • Galande should use his skill after Heytex.
• Lineup 2:
  • Laurel provides more damage but is pretty squishy in that position, so make sure she has Resolute on to be able to use her skill at least once.

Minutemen

• Lineup 1:
  • Kobayakawa’s UW gives a decent synergy with Benson, but it is not very good in Exploration, as you need to kill the enemy’s back-row as fast as you can, and you do not have many rounds in the fight.
• Lineup 2:
  • Roger provides a bit more focused damage, but only against the enemy’s front row.
• Lineup 3:
  • Less survivability but a bit more damage, but I am not a fan of this lineup.

But what about 4-skill heroes?

You definitely can max out some of the 4-skill heroes way prior to having all the Advanced heroes up there. Here are the ones you might use as substitutions:

• Minutemen
  • Rebecca – still might be viable with Kelly if you do not have many other options.
  • Chihiro – not a fan, as she attacks the front-row targets.
  • Alisa – can be used as a secondary tank until you have something better.
  • Coleman – can be used as a tank until you have something better.
• Vindicators
  • Max – not a fan, as he attacks the front-row targets.
  • Kate – she attacks the back row, but the damage is so low.
  • Betty – kinda sorta Casino alternative. If put in position 1 or 2, she can help your heroes attack first.
• Wildlings
  • Jessie – can be used as a secondary tank until you have something better.
  • Kin – can be used as a damage dealer until you have something better.
  • Irma – can be used as a tank until you have something better.
• Watchers
  • Suzuki – has some synergy with TAC damage dealers like Heytex, Victoria, and Elaine. Needs to be in position 2 and use her skill before the damage dealers.
  • Qian – some front row damage, but if I used her, it would be position two with Resolute just for a bit of front row damage.
  • Park Ji-Mi – can be used as a secondary tank until you have something better. Has some synergy with Victoria, but it is marginal/
  • Lunn – can be used as a tank until you have something better.