diff --git a/test/engine-event.test.js b/test/engine-event.test.js
index c929d92..d86f75c 100644
--- a/test/engine-event.test.js
+++ b/test/engine-event.test.js
@@ -20,6 +20,10 @@ describe('Engine: event', () => {
       canOrderDrinks: true
     }
   }
+
+  const awesomeEvent = {
+    type: 'awesome'
+  }
   /**
    * sets up a simple 'any' rule with 2 conditions
    */
@@ -92,6 +96,46 @@ describe('Engine: event', () => {
     engine.addFact('gender', 'male') // gender succeeds
   }
 
+  function setupWithConditionReference () {
+    const conditionName = 'awesomeCondition'
+    const conditions = {
+      any: [{ condition: conditionName }]
+    }
+    engine = engineFactory()
+    const ruleOptions = { conditions, event: awesomeEvent, priority: 100 }
+    const rule = factories.rule(ruleOptions)
+    engine.addRule(rule)
+    engine.setCondition(conditionName, {
+      all: [{
+        name: 'over 21',
+        fact: 'age',
+        operator: 'greaterThanInclusive',
+        value: 21
+      }]
+    })
+    engine.addFact('age', 21)
+  }
+
+  function setupWithUndefinedCondition () {
+    const conditionName = 'conditionThatIsNotDefined'
+    const conditions = {
+      any: [
+        { condition: conditionName, name: 'nameOfTheUndefinedConditionReference' },
+        {
+          name: 'over 21',
+          fact: 'age',
+          operator: 'greaterThanInclusive',
+          value: 21
+        }
+      ]
+    }
+    engine = engineFactory([], { allowUndefinedConditions: true })
+    const ruleOptions = { conditions, event: awesomeEvent, priority: 100 }
+    const rule = factories.rule(ruleOptions)
+    engine.addRule(rule)
+    engine.addFact('age', 21)
+  }
+
   context('engine events: simple', () => {
     beforeEach(() => simpleSetup())
 
@@ -602,4 +646,24 @@ describe('Engine: event', () => {
       expect(JSON.stringify(ruleResult)).to.equal(expected)
     })
   })
+
+  context('rule events: json serializing with condition reference', () => {
+    beforeEach(() => setupWithConditionReference())
+    it('serializes properties', async () => {
+      const { results: [ruleResult] } = await engine.run()
+      const expected = '{"conditions":{"priority":1,"any":[{"priority":1,"all":[{"name":"over 21","operator":"greaterThanInclusive","value":21,"fact":"age","factResult":21,"result":true}]}]},"event":{"type":"awesome"},"priority":100,"result":true}'
+      expect(JSON.stringify(ruleResult)).to.equal(expected)
+    })
+  })
+
+  context('rule events: json serializing with condition reference that is undefined', () => {
+    beforeEach(() => setupWithUndefinedCondition())
+    it('serializes properties', async () => {
+      const { results: [ruleResult] } = await engine.run()
+      const { conditions: { any: [conditionReference] } } = ruleResult
+      expect(conditionReference.result).to.equal(false)
+      const expected = '{"conditions":{"priority":1,"any":[{"name":"nameOfTheUndefinedConditionReference","condition":"conditionThatIsNotDefined"},{"name":"over 21","operator":"greaterThanInclusive","value":21,"fact":"age","factResult":21,"result":true}]},"event":{"type":"awesome"},"priority":100,"result":true}'
+      expect(JSON.stringify(ruleResult)).to.equal(expected)
+    })
+  })
 })
diff --git a/types/index.d.ts b/types/index.d.ts
index 81f08dc..827e79f 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -153,12 +153,22 @@ export type RuleSerializable = Pick<
   "conditions" | "event" | "name" | "priority"
 >;
 
+export type RuleResultSerializable = Pick<
+  Required<RuleResult>,
+  "name" | "event" | "priority" | "result"> & {
+    conditions: TopLevelConditionResultSerializable
+  }
+
 export interface RuleResult {
   name: string;
-  conditions: TopLevelCondition;
+  conditions: TopLevelConditionResult;
   event?: Event;
   priority?: number;
   result: any;
+  toJSON(): string;
+  toJSON<T extends boolean>(
+    stringify: T
+  ): T extends true ? string : RuleResultSerializable;
 }
 
 export class Rule implements RuleProperties {
@@ -176,6 +186,14 @@ export class Rule implements RuleProperties {
   ): T extends true ? string : RuleSerializable;
 }
 
+interface BooleanConditionResultProperties {
+  result?: boolean
+}
+
+interface ConditionResultProperties extends BooleanConditionResultProperties {
+  factResult?: unknown
+}
+
 interface ConditionProperties {
   fact: string;
   operator: string;
@@ -186,25 +204,46 @@ interface ConditionProperties {
   name?: string;
 }
 
+type ConditionPropertiesResult = ConditionProperties & ConditionResultProperties
+
 type NestedCondition = ConditionProperties | TopLevelCondition;
+type NestedConditionResult = ConditionPropertiesResult | TopLevelConditionResult;
 type AllConditions = {
   all: NestedCondition[];
   name?: string;
   priority?: number;
 };
+type AllConditionsResult = AllConditions & {
+  all: NestedConditionResult[]
+} & BooleanConditionResultProperties
 type AnyConditions = {
   any: NestedCondition[];
   name?: string;
   priority?: number;
 };
+type AnyConditionsResult = AnyConditions & {
+  any: NestedConditionResult[]
+} & BooleanConditionResultProperties
 type NotConditions = { not: NestedCondition; name?: string; priority?: number };
+type NotConditionsResult = NotConditions & {not: NestedConditionResult} & BooleanConditionResultProperties;
 type ConditionReference = {
   condition: string;
   name?: string;
   priority?: number;
 };
+type ConditionReferenceResult = ConditionReference & BooleanConditionResultProperties
 export type TopLevelCondition =
   | AllConditions
   | AnyConditions
   | NotConditions
   | ConditionReference;
+export type TopLevelConditionResult = 
+  | AllConditionsResult
+  | AnyConditionsResult
+  | NotConditionsResult
+  | ConditionReferenceResult
+export type TopLevelConditionResultSerializable =
+  | AllConditionsResult
+  | AnyConditionsResult
+  | NotConditionsResult
+  | ConditionReference
diff --git a/types/index.test-d.ts b/types/index.test-d.ts
index 6d5b37b..a7e1120 100644
--- a/types/index.test-d.ts
+++ b/types/index.test-d.ts
@@ -14,7 +14,11 @@ import rulesEngine, {
   Rule,
   RuleProperties,
   RuleResult,
-  RuleSerializable
+  RuleSerializable,
+  TopLevelConditionResult,
+  AnyConditionsResult,
+  AllConditionsResult,
+  NotConditionsResult
 } from "../";
 
 // setup basic fixture data
@@ -126,7 +130,20 @@ engine.on<{ foo: Array<string> }>('foo', (event, almanac, ruleResult) => {
 })
 
 // Run the Engine
-expectType<Promise<EngineResult>>(engine.run({ displayMessage: true }));
+const result = engine.run({ displayMessage: true })
+expectType<Promise<EngineResult>>(result);
+
+const topLevelConditionResult = result.then(r => r.results[0].conditions);
+expectType<Promise<TopLevelConditionResult>>(topLevelConditionResult)
+
+const topLevelAnyConditionsResult = topLevelConditionResult.then(r => (r as AnyConditionsResult).result);
+expectType<Promise<boolean | undefined>>(topLevelAnyConditionsResult)
+
+const topLevelAllConditionsResult = topLevelConditionResult.then(r => (r as AllConditionsResult).result);
+expectType<Promise<boolean | undefined>>(topLevelAllConditionsResult)
+
+const topLevelNotConditionsResult = topLevelConditionResult.then(r => (r as NotConditionsResult).result);
+expectType<Promise<boolean | undefined>>(topLevelNotConditionsResult)
 
 // Alamanac tests
 const almanac: Almanac = (await engine.run()).almanac;