diff --git a/module/system/dialogs.mjs b/module/system/dialogs.mjs
index b2bad97..8d45ef8 100644
--- a/module/system/dialogs.mjs
+++ b/module/system/dialogs.mjs
@@ -52,9 +52,11 @@
             form.serializeArray().map(item => {
               formData[item.name] = item.value;
             });
-            console.log("roll form data", formData);
+            // console.log("roll form data", formData);
             let NoD = parseInt(formData.ability,10);
             let Reroll = 0;
+            // difficulty
+            data.difficulty = (formData.difficulty != undefined) ? formData.difficulty : 7; 
             // maîtrise bonus
             if (formData.skill > 0 && formData.skill < 3){
               NoD += 1;
diff --git a/module/system/roll.mjs b/module/system/roll.mjs
index ea73912..ebd48ae 100644
--- a/module/system/roll.mjs
+++ b/module/system/roll.mjs
@@ -2,11 +2,11 @@ export class TotemRoll {
 
     static roll(actorId, label, NoD, Reroll = 0, params = {}){        
         const actor = game.actors.get(actorId);
-        let formula = '{' + NoD + "d10";
-        if (Reroll > 0){
-          formula += 'r' + Reroll;
+        let formula = '' + (parseInt(NoD,10) + parseInt(Reroll,10)) + "d10";
+        if (Reroll > 0 && params.difficulty != undefined){
+          formula += 'kh' + (parseInt(NoD,10) -1);
         }
-        formula += (params.difficulty != undefined) ? "}cs>" + params.difficulty : "}cs>7";
+        formula += (params.difficulty != undefined) ? "cs>" + params.difficulty : "cs>7";
         let roll = new Roll(formula, actor.getRollData());
         roll.toMessage({
           speaker: ChatMessage.getSpeaker({ actor: actor }),