diff --git a/examples/tests/controllerInterfaceTest.js b/examples/tests/controllerInterfaceTest.js
index 0dccd1209a..97ad9bbc38 100644
--- a/examples/tests/controllerInterfaceTest.js
+++ b/examples/tests/controllerInterfaceTest.js
@@ -4,8 +4,10 @@ ControllerTest = function() {
     var xbox = Controller.Hardware.GamePad;
     this.mappingEnabled = false;
     this.mapping = Controller.newMapping();
+    this.mapping.from(standard.LX).when([standard.LB, standard.RB]).to(actions.Yaw);
     this.mapping.from(standard.RX).to(actions.StepYaw);
     this.mapping.from(standard.RY).invert().to(actions.Pitch);
+    this.mapping.from(standard.RY).invert().to(actions.Pitch);
 
 
     var testMakeAxis = false;
diff --git a/libraries/controllers/src/controllers/UserInputMapper.cpp b/libraries/controllers/src/controllers/UserInputMapper.cpp
index 19a4b78207..2579c7dbec 100755
--- a/libraries/controllers/src/controllers/UserInputMapper.cpp
+++ b/libraries/controllers/src/controllers/UserInputMapper.cpp
@@ -738,6 +738,47 @@ Endpoint::Pointer UserInputMapper::parseEndpoint(const QJsonValue& value) {
     return result;
 }
 
+
+Conditional::Pointer UserInputMapper::conditionalFor(const QJSValue& condition) {
+    return Conditional::Pointer();
+}
+
+Conditional::Pointer UserInputMapper::conditionalFor(const QScriptValue& condition) {
+    if (condition.isArray()) {
+        int length = condition.property("length").toInteger();
+        Conditional::List children;
+        for (int i = 0; i < length; i++) {
+            Conditional::Pointer destination = conditionalFor(condition.property(i));
+            if (!destination) {
+                return Conditional::Pointer();
+            }
+            children.push_back(destination);
+        }
+        return std::make_shared<AndConditional>(children);
+    }
+
+    if (condition.isNumber()) {
+        return conditionalFor(Input(condition.toInt32()));
+    }
+
+    if (condition.isFunction()) {
+        return std::make_shared<ScriptConditional>(condition);
+    }
+
+    qWarning() << "Unsupported conditional type " << condition.toString();
+    return Conditional::Pointer();
+}
+
+Conditional::Pointer UserInputMapper::conditionalFor(const Input& inputId) const {
+    Locker locker(_lock);
+    auto iterator = _endpointsByInput.find(inputId);
+    if (_endpointsByInput.end() == iterator) {
+        qWarning() << "Unknown input: " << QString::number(inputId.getID(), 16);
+        return Conditional::Pointer();
+    }
+    return std::make_shared<EndpointConditional>(iterator->second);
+}
+
 Conditional::Pointer UserInputMapper::parseConditional(const QJsonValue& value) {
     if (value.isArray()) {
         // Support "when" : [ "GamePad.RB", "GamePad.LB" ]
@@ -764,7 +805,6 @@ Conditional::Pointer UserInputMapper::parseConditional(const QJsonValue& value)
     return Conditional::parse(value);
 }
 
-
 Filter::Pointer UserInputMapper::parseFilter(const QJsonValue& value) {
     Filter::Pointer result;
     if (value.isString()) {
@@ -780,7 +820,6 @@ Filter::Pointer UserInputMapper::parseFilter(const QJsonValue& value) {
     return result;
 }
 
-
 Filter::List UserInputMapper::parseFilters(const QJsonValue& value) {
     if (value.isNull()) {
         return Filter::List();
diff --git a/libraries/controllers/src/controllers/UserInputMapper.h b/libraries/controllers/src/controllers/UserInputMapper.h
index 319037fcb1..0a6ed3acad 100644
--- a/libraries/controllers/src/controllers/UserInputMapper.h
+++ b/libraries/controllers/src/controllers/UserInputMapper.h
@@ -143,6 +143,7 @@ namespace controller {
         friend class MappingBuilderProxy;
 
         void runMappings();
+
         static void applyRoutes(const RouteList& route);
         static bool applyRoute(const RoutePointer& route, bool force = false);
         void enableMapping(const MappingPointer& mapping);
@@ -151,6 +152,9 @@ namespace controller {
         EndpointPointer endpointFor(const QScriptValue& endpoint);
         EndpointPointer endpointFor(const Input& endpoint) const;
         EndpointPointer compositeEndpointFor(EndpointPointer first, EndpointPointer second);
+        ConditionalPointer conditionalFor(const QJSValue& endpoint);
+        ConditionalPointer conditionalFor(const QScriptValue& endpoint);
+        ConditionalPointer conditionalFor(const Input& endpoint) const;
         
         MappingPointer parseMapping(const QJsonValue& json);
         RoutePointer parseRoute(const QJsonValue& value);
diff --git a/libraries/controllers/src/controllers/impl/Conditional.h b/libraries/controllers/src/controllers/impl/Conditional.h
index 4d67d2871e..a216c8789f 100644
--- a/libraries/controllers/src/controllers/impl/Conditional.h
+++ b/libraries/controllers/src/controllers/impl/Conditional.h
@@ -28,6 +28,7 @@ namespace controller {
         using Pointer = std::shared_ptr<Conditional>;
         using List = std::list<Pointer>;
         using Factory = hifi::SimpleFactory<Conditional, QString>;
+        using Lambda = std::function<bool()>;
 
         virtual bool satisfied() = 0;
         virtual bool parseParameters(const QJsonValue& parameters) { return true; }
diff --git a/libraries/controllers/src/controllers/impl/RouteBuilderProxy.cpp b/libraries/controllers/src/controllers/impl/RouteBuilderProxy.cpp
index c0d0758e4e..d56d699c28 100644
--- a/libraries/controllers/src/controllers/impl/RouteBuilderProxy.cpp
+++ b/libraries/controllers/src/controllers/impl/RouteBuilderProxy.cpp
@@ -33,7 +33,6 @@ void RouteBuilderProxy::to(const QScriptValue& destination) {
 }
 
 void RouteBuilderProxy::to(const Endpoint::Pointer& destination) {
-    auto sourceEndpoint = _route->source;
     _route->destination = destination;
     _mapping->routes.push_back(_route);
     deleteLater();
@@ -56,6 +55,17 @@ QObject* RouteBuilderProxy::filterQml(const QJSValue& expression) {
     return this;
 }
 
+QObject* RouteBuilderProxy::when(const QScriptValue& expression) {
+    _route->conditional = _parent.conditionalFor(expression);
+    return this;
+}
+
+QObject* RouteBuilderProxy::whenQml(const QJSValue& expression) {
+    _route->conditional = _parent.conditionalFor(expression);
+    return this;
+}
+
+
 QObject* RouteBuilderProxy::filter(const QScriptValue& expression) {
     return this;
 }
diff --git a/libraries/controllers/src/controllers/impl/RouteBuilderProxy.h b/libraries/controllers/src/controllers/impl/RouteBuilderProxy.h
index 2303f6184f..4bcfba5acd 100644
--- a/libraries/controllers/src/controllers/impl/RouteBuilderProxy.h
+++ b/libraries/controllers/src/controllers/impl/RouteBuilderProxy.h
@@ -35,9 +35,11 @@ class RouteBuilderProxy : public QObject {
 
         Q_INVOKABLE void toQml(const QJSValue& destination);
         Q_INVOKABLE QObject* filterQml(const QJSValue& expression);
+        Q_INVOKABLE QObject* whenQml(const QJSValue& expression);
 
         Q_INVOKABLE void to(const QScriptValue& destination);
         Q_INVOKABLE QObject* debug(bool enable = true);
+        Q_INVOKABLE QObject* when(const QScriptValue& expression);
         Q_INVOKABLE QObject* filter(const QScriptValue& expression);
         Q_INVOKABLE QObject* clamp(float min, float max);
         Q_INVOKABLE QObject* pulse(float interval);
@@ -49,6 +51,7 @@ class RouteBuilderProxy : public QObject {
 
 private:
         void to(const Endpoint::Pointer& destination);
+        void conditional(const Conditional::Pointer& conditional);
         void addFilter(Filter::Lambda lambda);
         void addFilter(Filter::Pointer filter);
         UserInputMapper& _parent;