diff --git a/src/module/actor/entity.js b/src/module/actor/entity.js
index d817cbd..fed10ab 100644
--- a/src/module/actor/entity.js
+++ b/src/module/actor/entity.js
@@ -16,6 +16,7 @@ export class AcksActor extends Actor {
     this.computeEncumbrance();
     this.computeTreasure();
     this.computeBHR();
+    this.computeAAB();
 
     // Determine Initiative
     if (game.settings.get("acks", "initiative") != "group") {
@@ -817,4 +818,9 @@ export class AcksActor extends Actor {
         data.hp.max
     );
    };
+  computeAAB() {
+    const data = this.data.data;
+    
+    data.thac0.bba = 10 - data.thac0.throw;
+  }
 }
diff --git a/src/template.json b/src/template.json
index dbcfd78..7a68b19 100644
--- a/src/template.json
+++ b/src/template.json
@@ -30,6 +30,7 @@
         "thac0": {
           "value": 19,
           "bba": 0,
+          "throw": 10,
           "mod": {
             "missile": 0,
             "melee": 0
diff --git a/src/templates/actors/partials/character-attributes-tab.html b/src/templates/actors/partials/character-attributes-tab.html
index 3dd8cb6..e6d8174 100644
--- a/src/templates/actors/partials/character-attributes-tab.html
+++ b/src/templates/actors/partials/character-attributes-tab.html
@@ -147,8 +147,8 @@
                     </h4>
                     <div class="flexrow">
                         <div class="attribute-value">
-                            <input name="data.thac0.bba" type="text" value="{{data.thac0.bba}}" placeholder="0"
-                                data-dtype="Number" />
+                            <input name="data.thac0.throw" type="text" value="{{data.thac0.throw}}" placeholder=""
+                                data-dtype="Number" +/>
                         </div>
                     </div>
                 </li>
diff --git a/src/templates/actors/partials/monster-attributes-tab.html b/src/templates/actors/partials/monster-attributes-tab.html
index 0f26be0..5fb2494 100644
--- a/src/templates/actors/partials/monster-attributes-tab.html
+++ b/src/templates/actors/partials/monster-attributes-tab.html
@@ -41,7 +41,7 @@
                 <h4 class="attribute-name box-title" title="{{localize 'ACKS.AB'}}"><a>{{ localize "ACKS.ABShort" }}</a>
                 </h4>
                 <div class="attribute-value">
-                    <input name="data.thac0.bba" type="text" value="{{data.thac0.bba}}" placeholder="0"
+                    <input name="data.thac0.throw" type="text" value="{{data.thac0.throw}}" placeholder=""
                         data-dtype="Number" />
                 </div>
                 {{else}}