The Complete Last Asylum: Plague Research Tree Guide — All 13 Trees, the Right Priority Sequence, Key Nodes, and Costly Mistakes to Avoid
Understanding the Research System in Last Asylum: Plague
The research system in Last Asylum: Plague operates as a permanent account-wide multiplier — quietly amplifying construction speed, resource gathering, troop power, production output, and hero performance in the background. Because the Research Lab processes only one project at a time, and the full system spans 13 separate trees, the decisions you make about sequencing carry far more weight than most players initially appreciate.
What separates competitive players from everyone else usually isn't spending or hero luck — it's research order. Players who identify the right trees early and commit to them are stacking daily advantages that compound over weeks. Those who don't follow a deliberate sequence are spending those same weeks trying to close a gap that keeps widening.
For players pushing hard through event windows, having a reliable Diamond supply matters. LootBar is widely used among competitive players for top-up Last Asylum: Plague currency — it's notably cheaper than purchasing directly through the in-app store and consistently fast. If a major research push is coming up, stocking up via LootBar beforehand is worth the few minutes it takes.
Now let's go through every tree and build out the actual priority framework.
All 13 Research Trees — A Full Breakdown
Knowing what each tree actually does is essential before deciding where to invest. Here's the complete overview.
Development Tree
The Development tree functions as the backbone of your entire account progression. It governs construction time, research speed, troop training rate, healing efficiency, infirmary capacity, and — most importantly — grants access to the Training Grounds. Because its benefits touch essentially every other system in the game, unlocking Development nodes early creates a compounding effect that accelerates everything else you do from that point forward.
Economy Tree
Economy covers both resource production output and gathering speed, but its most distinctive function is one no other tree replicates: unlocking additional Herb Garden slots. Every extra Herb Garden available in your sanctuary is gated behind this tree. Since herbs consistently represent the tightest supply constraint in Last Asylum: Plague, this single feature makes Economy a high-priority target in the early game.
Hero Trees — Warlock, Ranger, and Warrior
Hero research is structured across three distinct faction-based trees. Each one delivers attack, defense, and HP bonuses exclusively for heroes belonging to that faction. These bonuses are genuinely impactful — but only when they align with the heroes you're actively fielding. Spreading investment across all three trees simultaneously means none of your squads benefit meaningfully. Choose one faction and invest there.
Soldiers, Squads, and Late-Game Trees
The remaining trees — Soldiers/Troops, four Squad-specific trees, Alliance Duel, Caravan Transport, Elite Troop, and the Offensive and Defensive Tactics trees — each address a specific slice of your account's capability. Some deliver immediate returns; others only become relevant at mid-to-late game stages. The priority breakdown below explains when each one deserves attention.
The Research Priority Order That Actually Works
This is where the real value of the guide lies. The following sequence produces the strongest compound progression for most accounts in Last Asylum: Plague.
Priority 1 — Development Tree, Before Anything Else
Development goes first, without exception. The reason is straightforward: its bonuses apply to every research project you'll ever run after it. Faster construction means buildings upgrade sooner. Higher research speed means every future timer — including the long ones — finishes earlier. More training throughput means your troop base scales faster. All of this feeds into every other system simultaneously.
Three Nodes to Target First Within Development
Don't just work through Development linearly. These three nodes deserve immediate attention:
Training Grounds Unlock — This is the first target. Training capacity is a direct ceiling on how fast you can build the troop base that powers combat, event participation, and territorial control. Unlocking this early removes a constraint that would otherwise slow you for weeks.
Construction Master Nodes — Each node shaves 5% off building construction time. The earlier these are unlocked, the more cumulative time they save across every upgrade your account ever runs. This is a permanent, ongoing return — not a one-time gain. The compounding value of getting these early is substantial.
Research Upgrade Nodes — Each adds 10% to your research speed. That figure may sound unremarkable at first, but at higher levels where research timers stretch to 20–30 days, a 10% reduction means getting three full days back on every long-timer project — permanently. Stack these early and the lifetime savings are enormous.
The remaining Development nodes — covering healing rate, resource production speed, and infirmary capacity — are still worth completing, just not ahead of these three.
Priority 2 — Economy Tree, Starting With Herb Gardens
Once Development is progressing well, Economy becomes your next focus.
Why Herb Gardens Come First Inside Economy
The Economy tree branches into two primary tracks: production output and gathering speed. Both are useful, but the Herb Garden unlock nodes take precedence over everything else in this tree. The reason is exclusivity — no other tree in the game offers additional Herb Garden slots. Securing these slots early means more consistent medicine output, a more stable hospital operation, and an economy that doesn't periodically choke on herb shortages.
After the Herb Garden nodes are secured, shift focus toward gathering speed rather than raw production output. Gathering speed scales more effectively over time because it compounds with how actively your squads are deployed across the map. As your account grows and squad deployment increases, the return on gathering speed grows with it. Production output from buildings, by comparison, hits a practical ceiling earlier.
Priority 3 — The Hero Faction Tree Matching Your Squad 1
Hero research trees are high-value — but their power is conditional. The operative rule: invest only in the faction tree that corresponds to the dominant faction in your Squad 1. Splitting investment across Warlock, Ranger, and Warrior simultaneously prevents any of your squads from reaching the thresholds where faction bonuses become significant.
How the Faction Bonus System Works
Each squad in Last Asylum: Plague has a built-in faction bonus mechanic tied to hero composition. Assembling three or more heroes of the same faction in a single squad activates a counter bonus that increases damage output. Push the count higher and the multiplier scales further. A fully homogeneous Squad 1 — all five heroes from one faction — simultaneously activates both the counter bonus and the attribute multiplier system.
This is exactly why concentrated investment beats a spread approach. Three same-faction heroes in Squad 1 yields a 5% attribute bonus. Four reaches 15%. Five triggers the full dual-bonus activation. Splitting research across all three faction trees means none of these thresholds are reached cleanly, and your squads underperform relative to their actual hero quality.
Identify the faction your strongest heroes belong to, structure Squad 1 around it, and direct all hero research investment exclusively to that tree.
Priority 4 — Alliance Duel Tree at Research Lab Level 15
The Alliance Duel tree unlocks the moment your Research Lab reaches Level 15. If you haven't hit that milestone yet, it's not an immediate concern — but the moment Lab 15 is reached, this tree should move up your priority list significantly.
Hit the Reward Unlock Nodes First
Within the Alliance Duel tree, the Tier 4–6 Reward Unlock nodes are the first targets. These nodes permanently expand the reward boxes you receive from Alliance Duel events, opening access to higher-tier boxes with substantially better contents — more resources, additional speedups, and higher-quality materials. Once unlocked, every subsequent Alliance Duel event automatically grants access to those upgraded reward tiers.
Delaying this means permanently leaving better loot on the table across every Alliance Duel you participate in until those nodes are completed. There's no recovering those missed rewards retroactively. Address it as soon as the Lab level requirement is met.
Late-Game Trees — When and How to Approach Them
Once the four core priorities are underway, the remaining trees fill in progressively:
Soldiers/Troops Tree — Covers troop load capacity, attack, defense, and HP. Among these, load capacity is worth prioritizing earlier because it directly enhances how efficiently your gathering squads operate. Combat-oriented stats within this tree become more impactful as PvP activity intensifies on your server.
Squad Trees — Four separate trees, one corresponding to each squad slot. Develop these alongside your hero faction tree to round out the combat capability of each squad systematically.
Elite Troop Tree — Required to access Tier 10 troops at the end-game stage. Don't let this slip until it becomes the bottleneck blocking late-stage progression. Keep it in your longer-term planning even if it's not an immediate priority.
Offensive and Defensive Tactics — Both trees carry Research Lab level prerequisites, so they unlock progressively as your Lab advances. Work through them when they become accessible; they'll fit naturally into your queue without requiring deliberate front-loading.
Mistakes That Set Players Back for Weeks
These errors show up consistently across accounts and are entirely preventable:
Treating quest guidance as a research roadmap. Quests are a useful progression tool, but they're designed to introduce features — not to optimize your research sequence. Use them for resources and milestones, not as a queue manager.
- Chasing nodes that appear powerful in isolation. Surface-level strength isn't the same as strategic value. Follow the priority sequence rather than pursuing whatever looks impactful on the tree at a given moment.
- Distributing hero tree investment across all three factions simultaneously. This is one of the most common and damaging mistakes. When investment is spread, no squad reaches the faction thresholds that activate meaningful bonuses. Pick one faction and go deep.
- Delaying the Herb Garden nodes in Economy until mid-game. This choice tends to create a supply crisis precisely when your account needs medicine most. Herb Gardens belong at the front of your Economy investment, not deferred until a shortage forces your hand.
- Ignoring the Alliance Duel tree after Lab 15 unlocks. Every duel event completed without those Tier 4–6 nodes active represents a permanent reward shortfall. The missed contents don't carry over — they're simply gone.
- Rushing into Offensive and Defensive Tactics too early. These trees have their place, but prioritizing them while Development and Economy still have high-value nodes outstanding is a sequencing mistake that weakens your foundation for the sake of late-game tools you're not yet positioned to use effectively.
Final Thoughts
The Last Asylum: Plague research system is one where early understanding creates durable, compounding advantages. Development leads the sequence — with Construction Master and Research Upgrade nodes as the immediate targets inside it. Economy follows, anchored by the Herb Garden unlocks. The Hero faction tree matching Squad 1 comes next, and Alliance Duel becomes a priority the moment Research Lab 15 is reached.
The core discipline is staying focused: don't spread investment across trees that aren't delivering immediate value, and never let the Research Lab sit idle. The players consistently setting the pace on their servers aren't necessarily outspending others — they're out-sequencing them. When you're ready to push through a significant research window, keeping your Diamond supply stocked through LootBar is a practical way to maintain momentum without overpaying.
