diff --git a/js/models/Attack.js b/js/models/Attack.js
index 599666b..a23e96f 100644
--- a/js/models/Attack.js
+++ b/js/models/Attack.js
@@ -75,5 +75,13 @@ var Attack = Backbone.Model.extend({
                 resoView.model.set("energyTotal", energy - damage);
             }
         });
+    },
+    undoDamage: function () {
+        var dpr = this.get("damagePerResonator");
+        _.each(resonatorViews, function (resoView, i) {
+            var energy = resoView.model.get("energyTotal");
+            var damage = dpr[i].damage;
+            resoView.model.set("energyTotal", energy + damage);
+        });
     }
 });
diff --git a/js/models/AttackCollection.js b/js/models/AttackCollection.js
index e9ba947..a8d0dbf 100644
--- a/js/models/AttackCollection.js
+++ b/js/models/AttackCollection.js
@@ -1,3 +1,12 @@
 var AttackCollection = Backbone.Collection.extend({
-    model: Attack
-});
\ No newline at end of file
+    model: Attack,
+    add: function(model, options) {
+        // attack.attack();
+        return Backbone.Collection.prototype.add.call(this, model, options);
+    },
+    pop: function(options) {
+        var popd = Backbone.Collection.prototype.pop.call(this, options);
+        popd.undoDamage();
+        return popd;
+    }
+});
diff --git a/js/views/AttackInfoView.js b/js/views/AttackInfoView.js
index da6d6d3..97d341b 100644
--- a/js/views/AttackInfoView.js
+++ b/js/views/AttackInfoView.js
@@ -1,7 +1,8 @@
 var AttackInfoView = Backbone.View.extend({
     events: {
         "mouseover": "showPosition",
-        "mouseout": "hidePosition"
+        "mouseout": "hidePosition",
+        "click .undo": "undoAttack"
     },
     showPosition: function () {
         playerView.model.set({x: this.model.get("x"), y: this.model.get("y")});
@@ -21,7 +22,15 @@ var AttackInfoView = Backbone.View.extend({
         var energyPortalMax = this.model.get("energyPortalMax");
         var percentage = Math.round(energyPortal / energyPortalMax * 1000) / 10;
         html += 'Dmg: ' + Math.round(damageTotal / 1000 * 10) / 10 + 'K, Portal: ' + Math.round(energyPortal / 1000 * 10) / 10 + 'K/' + energyPortalMax / 1000 + 'K (' + percentage + '%)';
+        if(this.model.collection.indexOf(this.model) == this.model.collection.length-1)
+            html += '&nbsp;-&nbsp;<span style="cursor: pointer" class="undo">undo</span>';
         this.$el.html(html);
         return this;
+    },
+    undoAttack: function() {
+        if(this.model.collection.indexOf(this.model) == this.model.collection.length-1) {
+            this.model.collection.pop();
+            playerView.hide();
+        }
     }
-});
\ No newline at end of file
+});
diff --git a/js/views/AttackListView.js b/js/views/AttackListView.js
index 3dcc5af..bae6749 100644
--- a/js/views/AttackListView.js
+++ b/js/views/AttackListView.js
@@ -1,8 +1,8 @@
 var AttackListView = Backbone.View.extend({
     initialize: function () {
         _.bindAll(this, "addOne", "render");
-        this.listenTo(this.collection, "add", this.addOne);
-        this.listenTo(this.collection, "reset", this.render)
+        //this.listenTo(this.collection, "add", this.addOne);
+        this.listenTo(this.collection, "add remove reset", this.render);
     },
     addOne: function (at) {
         var av = new AttackInfoView({
@@ -14,6 +14,6 @@ var AttackListView = Backbone.View.extend({
         this.$el.html("");
         this.collection.each(function (at, i) {
             this.addOne(at);
-        });
+        }, this);
     }
-});
\ No newline at end of file
+});
diff --git a/js/views/AttackSummaryView.js b/js/views/AttackSummaryView.js
index c051d64..ce39e6b 100644
--- a/js/views/AttackSummaryView.js
+++ b/js/views/AttackSummaryView.js
@@ -1,11 +1,12 @@
 var AttackSummaryView = Backbone.View.extend({
     initialize: function () {
         _.bindAll(this, "render");
-        this.listenTo(this.collection, "add change reset", this.render);
+        this.listenTo(this.collection, "add change remove reset", this.render);
         this.render();
     },
     events: {
-        "click .reset": "reset"
+        "click .reset": "reset",
+        "click .undo": "undo"
     },
     render: function () {
         var burstercount = [];
@@ -22,10 +23,16 @@ var AttackSummaryView = Backbone.View.extend({
                 htmls.push(b + 'x <span style="color:' + level_color[i + 1] + '">L' + (i + 1) + '</span>');
             }
         }
-        this.$el.html(htmls.join(", ") + ' <span style="cursor: pointer" class="reset">Reset</span>');
+        var resetSpan = ' <span style="cursor: pointer" class="reset">Reset</span>';
+        var undoSpan = ' <span style="cursor: pointer" class="undo">Undo</span>';
+        this.$el.html(htmls.join(", ") + resetSpan + " - " + undoSpan);
     },
     reset: function () {
         this.collection.reset();
         portal.reset();
+    },
+    undo: function () {
+        if(this.collection.length > 0)
+            this.collection.pop();
     }
 });
\ No newline at end of file
diff --git a/js/views/DamageHeatMapView.js b/js/views/DamageHeatMapView.js
index 5d150a7..3fe6497 100644
--- a/js/views/DamageHeatMapView.js
+++ b/js/views/DamageHeatMapView.js
@@ -5,7 +5,7 @@ var DamageHeatMapView = Backbone.View.extend({
     initialize: function () {
         _.bindAll(this, "render", "createDataset");
         this.listenTo(this.model, 'change', this.check);
-        this.listenTo(attacks, 'add', this.check);
+        this.listenTo(attacks, 'add remove', this.check);
     },
     check: function (a) {
         if (this.model.get("heatmap")) {