diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/android/AndroidResearchType.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/android/AndroidResearchType.kt
index 42b288ab3..8c75057fb 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/android/AndroidResearchType.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/android/AndroidResearchType.kt
@@ -1,6 +1,7 @@
 package ru.dbotthepony.mc.otm.android
 
 import com.google.common.collect.ImmutableList
+import com.google.common.collect.ImmutableSet
 import it.unimi.dsi.fastutil.objects.ObjectArraySet
 import net.minecraft.network.chat.Component
 import net.minecraft.network.chat.ComponentContents
@@ -10,6 +11,9 @@ import ru.dbotthepony.mc.otm.TranslatableComponent
 import ru.dbotthepony.mc.otm.capability.AndroidCapability
 import ru.dbotthepony.mc.otm.getKeyNullable
 import ru.dbotthepony.mc.otm.registry.MRegistry
+import java.util.*
+import kotlin.collections.HashSet
+import kotlin.collections.RandomAccess
 
 fun interface AndroidResearchFactory<R : AndroidResearch> {
 	fun factory(type: AndroidResearchType<*>, capability: AndroidCapability): R
@@ -55,6 +59,59 @@ private fun findAllChildren(
 	return add
 }
 
+class ListSet<T>(private val list: ImmutableList<T>) : List<T>, Set<T>, RandomAccess {
+	constructor(list: Collection<T>) : this(ImmutableList.copyOf(list))
+
+	private val set: ImmutableSet<T> by lazy { ImmutableSet.copyOf(list) }
+
+	override val size: Int
+		get() = list.size
+
+	override fun contains(element: T): Boolean {
+		return set.contains(element)
+	}
+
+	override fun containsAll(elements: Collection<T>): Boolean {
+		return set.containsAll(elements)
+	}
+
+	override fun get(index: Int): T {
+		return list[index]
+	}
+
+	override fun indexOf(element: T): Int {
+		return list.indexOf(element)
+	}
+
+	override fun isEmpty(): Boolean {
+		return list.isEmpty()
+	}
+
+	override fun iterator(): Iterator<T> {
+		return list.iterator()
+	}
+
+	override fun lastIndexOf(element: T): Int {
+		return list.lastIndexOf(element)
+	}
+
+	override fun listIterator(): ListIterator<T> {
+		return list.listIterator()
+	}
+
+	override fun listIterator(index: Int): ListIterator<T> {
+		return list.listIterator(index)
+	}
+
+	override fun spliterator(): Spliterator<T> {
+		return list.spliterator()
+	}
+
+	override fun subList(fromIndex: Int, toIndex: Int): List<T> {
+		return list.subList(fromIndex, toIndex)
+	}
+}
+
 open class AndroidResearchType<R : AndroidResearch>(
 	protected val factory: AndroidResearchFactory<R>
 ) {
@@ -97,6 +154,8 @@ open class AndroidResearchType<R : AndroidResearch>(
 	 *
 	 * C specify both B and A as it's prerequisites, [flatPrerequisites] will contain only B, when [definedPrerequisites] will contain
 	 * both B and A
+	 *
+	 * Returns list which also doubles as set (for contains method).
 	 */
 	val flatPrerequisites: List<AndroidResearchType<*>> by lazy {
 		val parentPrerequisites = findPrerequisites(definedPrerequisites)
@@ -108,14 +167,16 @@ open class AndroidResearchType<R : AndroidResearch>(
 			}
 		}
 
-		builder.build()
+		ListSet(builder.build())
 	}
 
 	/**
 	 * All prerequisite research, including indirect ones
+	 *
+	 * Returns list which also doubles as set (for contains method).
 	 */
 	val allPrerequisites: List<AndroidResearchType<*>> by lazy {
-		ImmutableList.copyOf(findAllPrerequisites(flatPrerequisites))
+		ListSet(findAllPrerequisites(flatPrerequisites))
 	}
 
 	/**
@@ -130,6 +191,8 @@ open class AndroidResearchType<R : AndroidResearch>(
 	 * * C is blocked by A
 	 *
 	 * Both C and B specify A as it's blockers, [flatBlocking] will contain only B, because C is blocked by A through B.
+	 *
+	 * Returns list which also doubles as set (for contains method).
 	 */
 	val flatBlocking: List<AndroidResearchType<*>> by lazy {
 		val list = ImmutableList.builder<AndroidResearchType<*>>()
@@ -151,11 +214,13 @@ open class AndroidResearchType<R : AndroidResearch>(
 			}
 		}
 
-		return@lazy list.build()
+		ListSet(list.build())
 	}
 
 	/**
 	 * All research directly unlocked by this research.
+	 *
+	 * Returns list which also doubles as set (for contains method).
 	 */
 	val flatUnlocks: List<AndroidResearchType<*>> by lazy {
 		val list = ImmutableList.builder<AndroidResearchType<*>>()
@@ -166,14 +231,32 @@ open class AndroidResearchType<R : AndroidResearch>(
 			}
 		}
 
-		return@lazy list.build()
+		ListSet(list.build())
 	}
 
 	/**
 	 * All research unlocked by this research, including indirect ones
+	 *
+	 * Returns list which also doubles as set (for contains method).
 	 */
 	val allUnlocks: List<AndroidResearchType<*>> by lazy {
-		ImmutableList.copyOf(findAllChildren(flatUnlocks))
+		ListSet(findAllChildren(flatUnlocks))
+	}
+
+	/**
+	 * All research blocked by this research, including indirect ones.
+	 *
+	 * Returns list which also doubles as set (for contains method)
+	 */
+	val allBlocking: List<AndroidResearchType<*>> by lazy {
+		val set = HashSet<AndroidResearchType<*>>()
+
+		for (research in flatBlocking) {
+			set.add(research)
+			set.addAll(research.allUnlocks)
+		}
+
+		ListSet(set)
 	}
 
 	fun factory(capability: AndroidCapability) = factory.factory(this, capability)