diff --git a/app/imports/api/creature/creatureProperties/methods/getSlotFillFilter.js b/app/imports/api/creature/creatureProperties/methods/getSlotFillFilter.js
index 1bba9421..177225b0 100644
--- a/app/imports/api/creature/creatureProperties/methods/getSlotFillFilter.js
+++ b/app/imports/api/creature/creatureProperties/methods/getSlotFillFilter.js
@@ -15,9 +15,30 @@ export default function getSlotFillFilter({slot, libraryIds}){
         slotFillerType: slot.slotType,
       }]
     });
+  } else if (slot.type === 'class') {
+    filter.$and.push({
+      $or: [{
+        type: 'classLevel',
+      },{
+        type: 'slotFiller',
+        slotFillerType: 'classLevel',
+      }]
+    });
+    filter.variableName = slot.variableName;
+
+    // Only search for levels the class needs
+    const levels = [];
+    if (slot.missingLevels && slot.missingLevels.length) {
+      levels.push(...slot.missingLevels);
+    } else if (slot.level) {
+      levels.push(slot.level);
+    }
+    if (levels.length) {
+      filter.level = {$or: levels};
+    }
   }
   let tagsOr = [];
-  let tagsNor = [];
+  let tagsNin = [];
   if (slot.slotTags && slot.slotTags.length){
     tagsOr.push({tags: {$all: slot.slotTags}});
   }
@@ -27,15 +48,15 @@ export default function getSlotFillFilter({slot, libraryIds}){
       if (extra.operation === 'OR'){
         tagsOr.push({tags: {$all: extra.tags}});
       } else if (extra.operation === 'NOT'){
-        tagsNor.push({tags: {$all: extra.tags}});
+        tagsNin.push(...extra.tags);
       }
     });
   }
   if (tagsOr.length){
     filter.$and.push({$or: tagsOr});
   }
-  if (tagsNor.length){
-    filter.$and.push({$nor: tagsNor});
+  if (tagsNin.length){
+    filter.$and.push({$nin: tagsNin});
   }
   if (!filter.$and.length){
     delete filter.$and;
diff --git a/app/imports/server/publications/library.js b/app/imports/server/publications/library.js
index f1d04175..00a45a5b 100644
--- a/app/imports/server/publications/library.js
+++ b/app/imports/server/publications/library.js
@@ -28,6 +28,7 @@ const LIBRARY_NODE_TREE_FIELDS = {
   amount: 1,
   // Class level
   level: 1,
+  variableName: 1,
   // Proficiency
   value: 1,
   // Reference
diff --git a/app/imports/server/publications/slotFillers.js b/app/imports/server/publications/slotFillers.js
index 3dd6d141..e97fa20f 100644
--- a/app/imports/server/publications/slotFillers.js
+++ b/app/imports/server/publications/slotFillers.js
@@ -88,3 +88,62 @@ Meteor.publish('slotFillers', function(slotId, searchTerm){
     });
   });
 });
+
+Meteor.publish('classFillers', function(classId){
+  let self = this;
+  if (!classId) return [];
+
+  this.autorun(function (){
+    let userId = this.userId;
+    if (!userId) {
+      return [];
+    }
+    // Get the class
+    let classProp = CreatureProperties.findOne(classId);
+    if (!classProp){
+      return [];
+    }
+
+    // Get all the ids of libraries the user can access
+    const user = Meteor.users.findOne(userId, {
+      fields: {subscribedLibraries: 1}
+    });
+    const subs = user && user.subscribedLibraries || [];
+    let libraries = Libraries.find({
+      $or: [
+        {owner: userId},
+        {writers: userId},
+        {readers: userId},
+        {_id: {$in: subs}},
+      ]
+    }, {
+      fields: {_id: 1, name: 1},
+    });
+    let libraryIds = libraries.map(lib => lib._id);
+
+    // Build a filter for nodes in those libraries that match the slot
+    let filter = getSlotFillFilter({slot: classProp, libraryIds});
+
+    this.autorun(function(){
+      // Get the limit of the documents the user can fetch
+      var limit = self.data('limit') || 50;
+      check(limit, Number);
+
+      let options = {
+        sort: {
+          name: 1,
+          order: 1,
+        },
+        fields: FIELDS,
+        limit,
+      };
+
+      self.autorun(function () {
+        self.setData('countAll', LibraryNodes.find(filter).count());
+      });
+      self.autorun(function () {
+        return [LibraryNodes.find(filter, options), libraries];
+      });
+    });
+  });
+});
diff --git a/app/imports/ui/creature/slots/LevelUpDialog.vue b/app/imports/ui/creature/slots/LevelUpDialog.vue
new file mode 100644
index 00000000..4eba1043
--- /dev/null
+++ b/app/imports/ui/creature/slots/LevelUpDialog.vue
@@ -0,0 +1,406 @@
+<template lang="html">
+  <dialog-base
+    :color="model.color"
+    dark-body
+  >
+    <template slot="toolbar">
+      <v-toolbar-title>
+        {{ model.name }}
+      </v-toolbar-title>
+      <v-spacer />
+      <v-text-field
+        v-model="searchInput"
+        prepend-inner-icon="mdi-magnify"
+        regular
+        clearable
+        hide-details
+        class="flex-grow-0"
+        style="flex-basis: 300px;"
+        :loading="searchLoading"
+        @change="searchValue = searchInput || undefined"
+        @click:clear="searchValue = undefined"
+      />
+    </template>
+    <property-description
+      text
+      :string="model.description"
+    />
+    <p>
+      {{ slotPropertyTypeName }} with tags:
+      <property-tags
+        v-for="(tags, index) in tagsSearched.or"
+        :key="index"
+        :tags="tags"
+        :prefix="index ? 'OR' : undefined"
+      />
+      <property-tags
+        v-for="(tags, index) in tagsSearched.not"
+        :key="index"
+        :tags="tags"
+        prefix="NOT"
+      />
+    </p>
+    <v-expansion-panels
+      multiple
+      inset
+    >
+      <template v-for="libraryNode in libraryNodes">
+        <v-expansion-panel
+          v-if="showDisabled || !libraryNode._disabledBySlotFillerCondition"
+          :key="libraryNode._id"
+          :model="libraryNode"
+          :data-id="libraryNode._id"
+          :class="{disabled: isDisabled(libraryNode)}"
+        >
+          <v-expansion-panel-header>
+            <template #default="{ open }">
+              <v-layout
+                align-center
+                class="flex-grow-0 mr-2"
+              >
+                <v-checkbox
+                  v-if="libraryNode._disabledByAlreadyAdded"
+                  class="my-0 py-0"
+                  hide-details
+                  :input-value="true"
+                  disabled
+                />
+                <v-checkbox
+                  v-else
+                  v-model="selectedNodeIds"
+                  class="my-0 py-0"
+                  hide-details
+                  :disabled="isDisabled(libraryNode)"
+                  :value="libraryNode._id"
+                  @click.stop
+                />
+              </v-layout>
+              <v-layout column>
+                <v-layout align-center>
+                  <tree-node-view :model="libraryNode" />
+                  <div
+                    v-if="libraryNode._disabledBySlotFillerCondition"
+                    class="error--text text-no-wrap text-truncate"
+                  >
+                    {{ libraryNode.slotFillerCondition }}
+                  </div>
+                </v-layout>
+                <div class="text-caption text-no-wrap text-truncate">
+                  {{ libraryNames[libraryNode.ancestors[0].id ] }}
+                </div>
+              </v-layout>
+              <div
+                v-if="libraryNode.slotQuantityFilled !== undefined && libraryNode.slotQuantityFilled !== 1"
+                class="text-overline flex-grow-0 text-no-wrap"
+                :class="{
+                  'error--text': isDisabled(libraryNode) &&
+                    libraryNode._disabledByQuantityFilled
+                }"
+              >
+                {{ libraryNode.slotQuantityFilled }} slots
+              </div>
+              <template v-if="open">
+                <v-btn
+                  icon
+                  class="flex-grow-0"
+                  @click.stop="openPropertyDetails(libraryNode._id)"
+                >
+                  <v-icon>mdi-window-restore</v-icon>
+                </v-btn>
+              </template>
+            </template>
+          </v-expansion-panel-header>
+          <v-expansion-panel-content>
+            <library-node-expansion-content :model="libraryNode" />
+          </v-expansion-panel-content>
+        </v-expansion-panel>
+      </template>
+    </v-expansion-panels>
+    <v-layout
+      v-if="(!$subReady.classFillers && !searchValue) || currentLimit < countAll"
+      column
+      align-center
+      justify-center
+      class="ma-3"
+    >
+      <v-btn
+        :loading="!$subReady.classFillers"
+        color="accent"
+        @click="loadMore"
+      >
+        Load More
+      </v-btn>
+    </v-layout>
+    <template v-if="!showDisabled && disabledNodeCount">
+      <v-layout
+        column
+        align-center
+        justify-center
+        class="ma-3"
+      >
+        <div>
+          Requirements of {{ disabledNodeCount }} properties were not met
+        </div>
+        <v-btn
+          class="mt-2"
+          elevation="0"
+          color="accent"
+          @click="showDisabled = true"
+        >
+          Show All
+        </v-btn>
+      </v-layout>
+    </template>
+    <template slot="actions">
+      <v-btn
+        text
+        @click="$store.dispatch('popDialogStack')"
+      >
+        Cancel
+      </v-btn>
+      <v-spacer />
+      <v-btn
+        text
+        color="primary"
+        :disabled="!dummySlot && !selectedNodeIds.length"
+        @click="$store.dispatch('popDialogStack', selectedNodeIds)"
+      >
+        <template v-if="model.spaceLeft">
+          {{ totalQuantitySelected }} / {{ model.spaceLeft }}
+        </template>
+        <template v-if="classId">
+          Insert
+        </template>
+        <template v-else>
+          Close Test
+        </template>
+      </v-btn>
+    </template>
+  </dialog-base>
+</template>
+
+<script lang="js">
+import CreatureVariables from '/imports/api/creature/creatures/CreatureVariables.js';
+import CreatureProperties from '/imports/api/creature/creatureProperties/CreatureProperties.js';
+import LibraryNodes from '/imports/api/library/LibraryNodes.js';
+import DialogBase from '/imports/ui/dialogStack/DialogBase.vue';
+import TreeNodeView from '/imports/ui/properties/treeNodeViews/TreeNodeView.vue';
+import PropertyDescription from '/imports/ui/properties/viewers/shared/PropertyDescription.vue'
+import resolve, { toString } from '/imports/parser/resolve.js';
+import { prettifyParseError, parse } from '/imports/parser/parser.js';
+// import evaluateString from '/imports/api/creature/computation/afterComputation/evaluateString.js';
+import getSlotFillFilter from '/imports/api/creature/creatureProperties/methods/getSlotFillFilter.js'
+import Libraries from '/imports/api/library/Libraries.js';
+import LibraryNodeExpansionContent from '/imports/ui/library/LibraryNodeExpansionContent.vue';
+import PropertyTags from '/imports/ui/properties/viewers/shared/PropertyTags.vue';
+import { getPropertyName } from '/imports/constants/PROPERTIES.js';
+import { clone } from 'lodash';
+
+export default {
+  components: {
+		DialogBase,
+    TreeNodeView,
+    PropertyDescription,
+    LibraryNodeExpansionContent,
+    PropertyTags,
+	},
+  props:{
+    classId: {
+      type: String,
+      default: undefined,
+    },
+    creatureId: {
+      type: String,
+      default: undefined,
+    },
+    dummySlot: {
+      type: Object,
+      default: undefined,
+    },
+  },
+  data(){return {
+    selectedNodeIds: [],
+    searchInput: undefined,
+    searchValue: undefined,
+    showDisabled: false,
+    disabledNodeCount: undefined,
+  }},
+  reactiveProvide: {
+    name: 'context',
+    include: ['creatureId'],
+  },
+  computed: {
+    tagsSearched(){
+      let or = [];
+      let not = [];
+      if (this.model.slotTags && this.model.slotTags.length){
+        or.push(this.model.slotTags);
+      }
+      this.model.extraTags?.forEach(extras => {
+        if (extras.tags?.length){
+          if(extras.operation === 'OR'){
+            or.push(extras.tags);
+          } else if (extras.operation === 'NOT'){
+            not.push(extras.tags);
+          }
+        }
+      });
+      return {or, not};
+    },
+    slotPropertyTypeName(){
+      if (!this.model) return;
+      if (!this.model.slotType) return 'Property';
+      let propName = getPropertyName(this.model.slotType);
+      return propName;
+    },
+  },
+  methods: {
+    loadMore(){
+      if (this.currentLimit >= this.countAll) return;
+      this._subs['classFillers'].setData('limit', this.currentLimit + 50);
+    },
+    openPropertyDetails(id){
+      this.$store.commit('pushDialogStack', {
+        component: 'library-node-dialog',
+        elementId: id,
+        data: {
+          _id: id,
+        },
+      });
+    },
+    isDisabled(node){
+      return node._disabledBySlotFillerCondition ||
+        node._disabledByAlreadyAdded ||
+      (
+        node._disabledByQuantityFilled &&
+        !this.selectedNodeIds.includes(node._id)
+      )
+    },
+  },
+  meteor: {
+    $subscribe: {
+      'classFillers'(){
+        return [this.classId, this.searchValue || undefined]
+      },
+    },
+    searchLoading(){
+      return !!this.searchValue && !this.$subReady.classFillers;
+    },
+    model(){
+      if (this.classId){
+        return CreatureProperties.findOne(this.classId);
+      } else if (this.dummySlot) {
+        let model = clone(this.dummySlot)
+        if (!model.quantityExpected) model.quantityExpected = {};
+        model.quantityExpected.value = +model.quantityExpected.calculation;
+        model.spaceLeft = model.quantityExpected.value;
+        return model;
+      }
+    },
+    variables() {
+      if (!this.creatureId) return {};
+      return CreatureVariables.findOne({ _creatureId: this.creatureId }) || {};
+    },
+    currentLimit(){
+      return this._subs['classFillers'].data('limit') || 50;
+    },
+    countAll(){
+      return this._subs['classFillers'].data('countAll');
+    },
+    alreadyAdded(){
+      let added = new Set();
+      if (!this.model.unique) return added;
+      let ancestorId;
+      if (this.model.unique === 'uniqueInSlot'){
+        ancestorId = this.model._id;
+      } else if (this.model.unique === 'uniqueInCreature'){
+        ancestorId = this.creatureId;
+      }
+      CreatureProperties.find({
+        'ancestors.id': ancestorId,
+        libraryNodeId: {$exists: true},
+        removed: {$ne: true},
+      }, {
+        fields: {libraryNodeId: 1},
+      }).forEach(prop => {
+        added.add(prop.libraryNodeId);
+      });
+      return added;
+    },
+    totalQuantitySelected(){
+      let quantitySelected = 0;
+      LibraryNodes.find({
+        _id: {$in: this.selectedNodeIds}
+      }, {
+        fields: {slotQuantityFilled: 1},
+      }).forEach(node => {
+        if (Number.isFinite(node.slotQuantityFilled)){
+          quantitySelected += node.slotQuantityFilled;
+        } else {
+          quantitySelected += 1;
+        }
+      });
+      return quantitySelected;
+    },
+    spaceLeft(){
+      if (!this.model.quantityExpected || this.model.quantityExpected.value === 0) return undefined;
+      return this.model.spaceLeft - this.totalQuantitySelected;
+    },
+    libraryNames(){
+      let names = {};
+      Libraries.find().forEach(lib => names[lib._id] = lib.name)
+      return names;
+    },
+    libraryNodes(){
+      let filter = getSlotFillFilter({slot: this.model});
+      let nodes = LibraryNodes.find(filter, {
+        sort: {name: 1, order: 1}
+      }).fetch();
+      let disabledNodeCount = 0;
+      // Mark classFillers whose condition isn't met or are too big to fit
+      // the quantity to fill
+      nodes.forEach(node => {
+        if (node.slotFillerCondition){
+          try {
+            let parseNode = parse(node.slotFillerCondition);
+            const {result: resultNode} = resolve('reduce', parseNode, this.variables);
+            if (resultNode?.parseType === 'constant'){
+              if (!resultNode.value){
+                node._disabledBySlotFillerCondition = true;
+                disabledNodeCount += 1;
+              }
+            } else {
+              node._disabledBySlotFillerCondition = true;
+              node._conditionError = toString(resultNode);
+              disabledNodeCount += 1;
+            }
+          } catch (e){
+            console.warn(e);
+            let error = prettifyParseError(e);
+            node._disabledBySlotFillerCondition = true;
+            node._conditionError = error;
+            disabledNodeCount += 1;
+          }
+        }
+        let quantityToFill = node.type === 'slotFiller' ? node.slotQuantityFilled : 1;
+        if (
+          quantityToFill > this.spaceLeft
+        ){
+          node._disabledByQuantityFilled = true;
+        }
+        if (this.alreadyAdded.has(node._id)){
+          node._disabledByAlreadyAdded = true;
+        }
+      });
+      this.disabledNodeCount = disabledNodeCount;
+      return nodes;
+    },
+  }
+}
+</script>
+
+<style lang="css" scoped>
+  .disabled {
+    opacity: 0.7;
+  }
+</style>
diff --git a/app/imports/ui/dialogStack/DialogComponentIndex.js b/app/imports/ui/dialogStack/DialogComponentIndex.js
index 4f0f96e0..8fb87bc7 100644
--- a/app/imports/ui/dialogStack/DialogComponentIndex.js
+++ b/app/imports/ui/dialogStack/DialogComponentIndex.js
@@ -10,6 +10,7 @@ const DeleteUserAccountDialog = () => import('/imports/ui/user/DeleteUserAccount
 const ExperienceInsertDialog = () => import( '/imports/ui/creature/experiences/ExperienceInsertDialog.vue');
 const ExperienceListDialog = () => import( '/imports/ui/creature/experiences/ExperienceListDialog.vue');
 const InviteDialog = () => import('/imports/ui/user/InviteDialog.vue');
+const LevelUpDialog = () => import('/imports/ui/creature/slots/LevelUpDialog.vue');
 const LibraryCreationDialog = () => import('/imports/ui/library/LibraryCreationDialog.vue');
 const LibraryEditDialog = () => import('/imports/ui/library/LibraryEditDialog.vue');
 const LibraryNodeCreationDialog = () => import('/imports/ui/library/LibraryNodeCreationDialog.vue');
@@ -36,6 +37,7 @@ export default {
   ExperienceInsertDialog,
   ExperienceListDialog,
   InviteDialog,
+  LevelUpDialog,
   LibraryCreationDialog,
   LibraryEditDialog,
   LibraryNodeCreationDialog,
diff --git a/app/imports/ui/properties/viewers/ClassViewer.vue b/app/imports/ui/properties/viewers/ClassViewer.vue
index 44322a52..d474faec 100644
--- a/app/imports/ui/properties/viewers/ClassViewer.vue
+++ b/app/imports/ui/properties/viewers/ClassViewer.vue
@@ -47,24 +47,20 @@
         :cols="{cols: 12}"
       >
         <v-btn
-          v-if="model.missingLevels && model.missingLevels.length"
           outlined
           color="accent"
+          data-id="level-up-btn"
+          @click="levelUpDialog"
         >
           <v-icon left>
             mdi-plus
           </v-icon>
-          Get Missing Levels
-        </v-btn>
-        <v-btn
-          v-else
-          outlined
-          color="accent"
-        >
-          <v-icon left>
-            mdi-plus
-          </v-icon>
-          Level Up
+          <template v-if="model.missingLevels && model.missingLevels.length">
+            Get Missing Levels 
+          </template>
+          <template v-else>
+            Level Up
+          </template> 
         </v-btn>
       </property-field>
       <property-description
@@ -85,6 +81,18 @@ export default {
       default: {},
     },
   },
+  methods: {
+    levelUpDialog(){
+      this.$store.commit('pushDialogStack', {
+        component: 'level-up-dialog',
+        elementId: 'level-up-btn',
+        data: {
+          creatureId: this.creatureId,
+          classId: this.model._id,
+        },
+      });
+    },
+  }
 }
 </script>