Resource gathering is one of the fundamental mechanics in Last Fortress: Underground and a critical activity on Mondays. Let’s look at its basics and then break down all its aspects.
The basics:
- There are four standard resources you can mine:
- Stone
- Iron
- Z-coin
- Alloy (S3+)
- These resources are spawned as mines on the World Map.
- You can use your APCs to gather resources from the mines.
- If you deplete a mine, you will receive Resource Chests.
- Gathering efficiency depends on Load (how much you can carry) and Speed (how fast you gather).
Note: Aluminum is different from other resources. Read more about it here – Bauxite Mines.
What Affects Gathering
The two main attributes that will affect your gathering in this game are Gathering Speed and Load.
I have covered in detail every factor influencing gathering at the beginning of this section here – Gathering Lineup. I reformatted that information into tables below:
What affects gathering speed?
| Category | Subcategory | Details | Effect (max) |
|---|---|---|---|
| Research (Lab) | Efficient Gathering | Fortress Upgrades -> World Exploration | +40% |
| All For One | Power Up -> Faction Enhancement | +20% (4-5 same faction heroes in gathering lineup) | |
| Efficient Gathering | Alliance Techs -> Alliance Commemoration | +20% (on Alliance Duel Gathering Day) | |
| Solari Heroes | Laura Chen | First skill | Grants a truck for gathering, no heroes required |
| Grace | Third skill | +20% gathering speed for z-coins | |
| Mario | Second skill | +20% gathering speed for iron | |
| Pheidias | Second skill | +20% gathering speed for stone | |
| Combat Heroes | Minutemen | Brom and Cindy | +15% each |
| Vindicators | Matthew and Ivan | +20% and +15% respectively | |
| Wildlings | Dean | +15% | |
| Watchers | David and Park Ji-Mi | +25% and +20% respectively | |
| Items | Gathering Boost | - | +50% buff (excluding z-coins) |
| Fresh Fish Soup | Requires Russel | +5% gathering speed for 8 hrs (overrides other speed buffs) | |
| VIP Level | Level 15 | - | +22% gathering speed (lower levels grant less) |
| Alliance Orders | Fast as a Hare | Can be initiated by alliance's R4 or leader | +20% gathering speed for all members for 12 hrs |
| City Conditions | Fully Repaired City | - | +50% gathering speed on its territory |
| Policy Card | Mineshaft | 3-star policy card | +20% speed boost (+5% more when fully upgraded) |
What affects load?
| Category | Subcategory | Details | Effect (max) |
|---|---|---|---|
| Research (Lab) | Load Optimizations | Fortress Upgrades -> World Exploration | +50% |
| Load Optimizations I | Lineup Boost -> Deployment Queue | +20% | |
| Load Optimizations II | Lineup Boost -> Deployment Queue | +20% | |
| Load Enhancements | Alliance Techs -> Alliance Commemoration | +20% | |
| Combat Heroes | All with Gathering skills | - | +100 load each |
| Wildlings | Irma | +20% | |
| Watchers | David | +20% | |
| Solari Heroes | Erica | Second skill | +10% |
| Mario | Fourth skill | +10% | |
| Policy Card | Coach Reinforcement | 3-star policy card | +20% load boost (+5% more when fully upgraded) |
| APC Upgrade | - | At level 20 | +100 load |
| Alliance Skill | Pack Training | - | +25% |
| Floating Fortress | Army Lab | Only for T10 troops | +25% |
Gathering Lineups
This I have also covered here – Gathering Lineup Examples – in the Lineup guide.
Here’s the summary of that section:
Before completion of the “All For One, One For All” research, the faction of gathering heroes in a lineup does not matter. You can maximize load and gathering speed with any combination. For instance:
- Truck one: Park Ji-Mi, David, Dean, Ivan, and Matthew
- Truck two: Irma, Cindy, Brom, Doris, and any other hero
- Truck three: Any heroes
After completing the “All For One, One For All” research, lineups can be rearranged for better efficiency. They would look something like this:
- Truck one: David, Park Ji-Mi, Dean, and any 2 Watchers
- Truck two: Matthew, Ivan, Irma, Kate, and any Vindicator
- Truck three: Brom, Cindy, Doris, and any 2 Minutemen or 1 Minutemen and 1 hero of any faction
Since the Wildlings faction only has one gathering speed hero, they are split and used in different lineups.
A traveling speed hero can be added to the second and third trucks for increased efficiency. If needed, these heroes can be replaced with any other hero of the same faction.
Here are the screenshots of my four gathering lineups:
General Strategy
Let’s now consider how you will generally want to gather resources, excluding Mondays.
First: I must say that gathering is not the most effective way of getting resources. Since they upped the number of bots on the map, it is better to farm bots (or players if that’s your thing 👹).
Gather only if:
- You are out of durability
- Always leave five on each APC, whatever you’re doing.
- You are going to bed
- It’s Monday
Second: It is better to mine level three mines during the day. Basically, you just want more Resource Chests to have a better chance of getting the 24-hour gathering speed buff.
How does that work? Let’s do some math here (yay):
I will use my first gathering lineup (see above) with two gathering speed heroes with their gathering speed skills maxed. As for resource-specific buffs, Mario’s second skill is level five, and Pheidas’ second skill is level four.
The numbers can be used for relative comparison, regardless of what you use. Also, we are looking only at the chests per hour effectiveness.
- 2:31 – 450 iron – 3 chests
- 1.17 chests an hour
- 2:27 – 600 stone – 3 chests
- 1.2 chests an hour
- 4:30 – 800 iron – 4 chests
- 0.88 chests an hour
- 4:54 – 1200 stone – 4 chests
- 0.81 chests an hour
- 7:54 – 1400 iron – 5 chests
- 0.63 chests per hour
- 8:10 – 2000 stone – 5 chests
- 0.61 chests per hour
Now, let’s assume that I am trying to play as effectively as I can. I spend eight hours a day sleeping (yeah, sure, but let’s roll with it), so I have 16 hours left. Of those 16 hours, let’s say at least two hours my cars are doing something besides gathering, which leaves me with 14 hours.
- In these 14 hours, I can fully gather five level-three stone mines with my first APC. That’s 15 level-three resource chests.
- If I go for level-four stone mines, I will be able to mine three mines fully, which is 12 level-four chests.
- And level-five mines will provide me with only five chests. Let’s say I squeezed one more gathering trip and mined them twice, so I have ten level-five chests.
Now, let’s take a look at the probabilities of getting stuff from these chests:
- Getting a gathering buff – 0.5% across all chests
- 15 chests – 7.2%
- 12 chests – 5.8%
- 10 chests – 4.88%
- Getting 900 recruitment points – 0.1% for a lvl-3 chest, 0.2% for lvl-4, and 0.3% for lvl-5.
- 15 lvl-3 chests – 1.4%
- 12 lvl-4 chests – 2.3%
- 10 lvl-5 chests – 2.9%
Results: It is better to gather level-three mines for a better chance of getting the 24-hr gathering buff. But, if you want to aim for recruitment points, gathering level-five mines is very marginally better.
Let’s assume that my gathering APCs are perfectly balanced, and I spend the same amount of time fully gathering a lvl-3 mine with each of the APCs (including the one granted by Laura Chen).
Then, let’s assume a less ideal scenario where I get 12 chests a day with each APC instead of 15.
5*12 = 60 lvl-3 chests a day
Opening them gives me a 25% chance of getting the gathering buff. Although still not 100% guaranteed, I have a good chance of getting at least one such buff per week to use before Monday.
Here’s how the cumulative probability is calculated: (you can skip it, boring stuff)
If you have 10 chests, each with a 0.5% chance of getting an item, you can calculate the cumulative probability of getting at least one item across all 10 chests by first calculating the probability of NOT getting the item from any single chest, which is 1−0.005=0.995.
The probability of not getting an item from all ten chests would then be 0.995^10.
Finally, the cumulative probability of getting at least one item in 10 tries is the complement of not getting any at all, which is 1−0.995^10.
Using this formula:
1−0.995^10 ≈ 1−0.9512 ≈ 0.0488 or 4.88%
So, the cumulative probability of getting at least one item (with a 0.5% chance) from 10 chests is approximately 4.88%.
Monday Strategy
I have also covered this part here – Monday – The Gathering Day – in my Alliance Duel (AD) guide.
I will try a different format here and walk you through the process step by step. But before that, let’s answer one question:
What is better to mine during AD, iron or stone?
The short answer is iron.
The longer answer is – it depends. If you have to choose from a discovered level 8 stone mine and a basic level 5 iron mine, it would be better to go for the stone one because it contains much more resources.
Let’s do some more math (yay, again).
I will use the time from the probability calculations before, but I will add the amount of resources you get from the maxed out Unexpected Prank (UP for short) research from the Alliance Commemoration tree that gives 50 resources per hour of gathering.
- 2:31 – 450 iron
- + 100 iron from UP
- 2:27 – 600 stone – 3 chests
- +100 stone from UP
- 4:30 – 800 iron – 4 chests
- +200 iron from UP
- 4:54 – 1200 stone – 4 chests
- +200 stone from UP
- 7:54 – 1400 iron – 5 chests
- +350 iron from UP
- 8:10 – 2000 stone – 5 chests
- +400 stone from UP
So, without applying any buffs and considering any research that increases the amount of AD points, here’s what you get:
- Level 3 iron mine – 550*45 = 24,750 points
- Level 3 stone mine – 700*30 = 21,000 points
- Level 4 iron mine – 1000*45 = 45,000 points
- Level 4 stone mine – 1400*30 = 42,000 points
- Level 5 iron mine – 1750*45 = 78,750 points
- Level 5 stone mine – 2400*30 = 72,000 points
Result: Among default mines (lvl 3-5), iron is the best one to mine for AD points.
Now, how to get the most out of the first AD day:
Update: Incorporate Aluminum mining in the schedule below.
- Sunday preparations: This one will depend on your time zone.
- If the server reset happens during the daytime for you, you can time things a bit better. You will want to send your APCs gathering so that they all finish within the first hour after the reset, and you will use the 50% or 100% buff card as efficiently as you can.
- If the reset happens at night for you, let’s say at 5 AM, you’d want to make sure to send the APCs gathering so that they return when you’re already awake to be able to use the buff cards.
- 00:00-06:00: You used your buff card for the first APC return (I suggest using up to four 50% cards during the day instead of one 100% card).
- Now, use the gathering buff. You should have the 24-hr prepared, but if you don’t, at least get three 8-hr ones from the Alliance Shop if possible.
- Depending on how many Personal Armaments Race points you got, you’d want to either send your APCs to gather level-four iron mines to get the second race reward or send them to gather level-five iron mines for more AD points. In both cases, you want to use another buff card just before the APCs return.
- 06:00-12:00: Here, I usually spend around 30-60 minutes getting the trade race points and all the routine things you usually do. Then, either send APCs to gather level-three mines twice during these six hours or level-five iron mines. Whether you use a buff card or not depends on your AD points. If you do not have much research done in the Alliance Commemoration tree, you might need to use one.
- 12:00-18:00: This is the Mutants race activity, so rally mutants during these hours and send the APCs gathering again.
- 18:00-24:00: Complete the Kill Zombies activity for the race here as early as possible and send APCs gathering again. If you have already gotten the 4-mil chest and you’re far ahead of your AD opponent, it will not matter if your APCs return before the reset. But, if you still need more points for rewards or for overall AD points, make sure to choose those mines you will finish by the reset.
This is an ideal course of action that often can be disrupted by an enemy alliance attacking you or some in-game events that will require your attention.