Fix Rolemaster low-end open roll math

README.md

@@ -64,7 +64,7 @@ Gameplay capabilities now include:
 - Admin user management is integrated into workspace screen toggles (`Play`, `Campaign Management`, `Admin`)
 - Rolemaster expression validation currently recognizes `2d10+48`, `d100+4`, and `d100!+85`, including Rolemaster-only negative modifiers such as `d100-15`
 - Rolemaster open-ended percentile skills and skill-group defaults now persist a nullable `FumbleRange` field, while D6 and D&D rows migrate forward unchanged
-- Rolemaster roll execution now supports initiative (`2d10+x`), standard percentile (`d100+x`), and open-ended percentile (`d100!+x`) with recursive high-end chaining and low-end subtraction based on `FumbleRange`
+- Rolemaster roll execution now supports initiative (`2d10+x`), standard percentile (`d100+x`), and open-ended percentile (`d100!+x`) with recursive high-end chaining and low-end subtraction based on `FumbleRange`; low-end trigger rolls are shown for auditability but do not count toward the total
 - Compact campaign-log summaries stay dense for Rolemaster rolls, while lazy-loaded roll detail includes ordered die metadata for each open-ended follow-up step
 - Startup migration coverage is validated against a copied temp-file instance of `RpgRoller/App_Data/rpgroller.development.db` before feature work is considered complete
 

RpgRoller.Tests/Api/RolemasterApiTests.cs

@@ -54,9 +54,9 @@ public sealed class RolemasterApiTests : ApiTestBase
         var logPage = await GetAsync<CampaignLogPage>(client, $"/api/campaigns/{campaign.Id}/log/page?limit=5");
         var detail = await GetAsync<CampaignRollDetail>(client, $"/api/rolls/{roll.RollId}");
 
-        Assert.Equal(-119, roll.Result);
+        Assert.Equal(-124, roll.Result);
-        Assert.Equal("5-(97+100+12)+85=-119", roll.Breakdown);
+        Assert.Equal("(05) -97 -100 -12 +85 = -124", roll.Breakdown);
-        Assert.Equal("5 - (97 + 100 + 12) | open-ended low", Assert.Single(logPage.Entries).SummaryText);
+        Assert.Equal("(05) -97 -100 -12 | open-ended low", Assert.Single(logPage.Entries).SummaryText);
         Assert.Equal(roll.Breakdown, detail.Breakdown);
         Assert.Collection(
             detail.Dice,
@@ -64,7 +64,7 @@ public sealed class RolemasterApiTests : ApiTestBase
             {
                 Assert.Equal(RollDieKinds.RolemasterOpenEndedInitial, die.Kind);
                 Assert.Equal(1, die.Sequence);
-                Assert.Equal(5, die.SignedContribution);
+                Assert.Null(die.SignedContribution);
             },
             die =>
             {

RpgRoller.Tests/Services/ServiceRolemasterRollTests.cs

@@ -127,9 +127,9 @@ public sealed class ServiceRolemasterRollTests
         var roll = ServiceTestSupport.GetValue(service.RollSkill(session, skill.Id, "public"));
         var logPage = ServiceTestSupport.GetValue(service.GetCampaignLogPage(session, campaign.Id, limit: 5));
 
-        Assert.Equal(-119, roll.Result);
+        Assert.Equal(-124, roll.Result);
-        Assert.Equal("5-(97+100+12)+85=-119", roll.Breakdown);
+        Assert.Equal("(05) -97 -100 -12 +85 = -124", roll.Breakdown);
-        Assert.Equal("5 - (97 + 100 + 12) | open-ended low", Assert.Single(logPage.Entries).SummaryText);
+        Assert.Equal("(05) -97 -100 -12 | open-ended low", Assert.Single(logPage.Entries).SummaryText);
         Assert.Collection(
             roll.Dice,
             die =>
@@ -137,7 +137,7 @@ public sealed class ServiceRolemasterRollTests
                 Assert.Equal(5, die.Roll);
                 Assert.Equal(1, die.Sequence);
                 Assert.Equal(RollDieKinds.RolemasterOpenEndedInitial, die.Kind);
-                Assert.Equal(5, die.SignedContribution);
+                Assert.Null(die.SignedContribution);
             },
             die =>
             {

RpgRoller/Components/Pages/HomeControls/RollDiceStrip.razor.cs

@@ -23,6 +23,9 @@ public partial class RollDiceStrip
 
     private static string RollDieDisplay(RollDieResult die)
     {
+        if (string.Equals(die.Kind, RollDieKinds.RolemasterOpenEndedInitial, StringComparison.Ordinal) && !die.SignedContribution.HasValue)
+            return $"({die.Roll:00})";
+
         return die.Kind switch
         {
             RollDieKinds.RolemasterOpenEndedHigh        => $"+{die.Roll}",
@@ -101,7 +104,7 @@ public partial class RollDiceStrip
                 labels.Add("Rolemaster percentile");
                 break;
             case RollDieKinds.RolemasterOpenEndedInitial:
-                labels.Add("Rolemaster open-ended initial");
+                labels.Add(die.SignedContribution.HasValue ? "Rolemaster open-ended initial" : "Rolemaster low-end trigger (ignored in total)");
                 break;
             case RollDieKinds.RolemasterOpenEndedHigh:
                 labels.Add($"Rolemaster high follow-up (+{die.Roll})");

RpgRoller/Services/GameService.cs

@@ -1007,12 +1007,13 @@ public sealed class GameService : IGameService
     {
         var initialRoll = m_DiceRoller.Roll(expression.Sides);
         var followUpRolls = new List<int>();
+        int? initialContribution = initialRoll <= fumbleRange ? null : initialRoll;
         var dice = new List<RollDieResult>
         {
-            CreateRolemasterDie(initialRoll, 1, RollDieKinds.RolemasterOpenEndedInitial, initialRoll)
+            CreateRolemasterDie(initialRoll, 1, RollDieKinds.RolemasterOpenEndedInitial, initialContribution)
         };
 
-        var baseTotal = initialRoll;
+        var baseTotal = initialRoll <= fumbleRange ? 0 : initialRoll;
         var subtractFollowUps = false;
         if (initialRoll >= 96)
         {
@@ -1134,7 +1135,7 @@ public sealed class GameService : IGameService
         return followUpRolls;
     }
 
-    private static RollDieResult CreateRolemasterDie(int roll, int sequence, string kind, int signedContribution)
+    private static RollDieResult CreateRolemasterDie(int roll, int sequence, string kind, int? signedContribution)
     {
         return new(roll, false, false, false, false, kind == RollDieKinds.RolemasterOpenEndedHigh, sequence, kind, signedContribution);
     }
@@ -1150,6 +1151,18 @@ public sealed class GameService : IGameService
 
     private static string BuildRolemasterOpenEndedBreakdown(int initialRoll, IReadOnlyList<int> followUpRolls, bool subtractFollowUps, int modifier, int total)
     {
+        if (subtractFollowUps)
+        {
+            var segments = new List<string> { $"({FormatRolemasterTriggerRoll(initialRoll)})" };
+            segments.AddRange(followUpRolls.Select(roll => $"-{roll}"));
+            if (modifier > 0)
+                segments.Add($"+{modifier}");
+            else if (modifier < 0)
+                segments.Add(modifier.ToString());
+
+            return $"{string.Join(" ", segments)} = {total}";
+        }
+
         var core = initialRoll.ToString();
         if (followUpRolls.Count > 0)
         {
@@ -1160,6 +1173,11 @@ public sealed class GameService : IGameService
         return BuildModifierBreakdown(core, modifier, total);
     }
 
+    private static string FormatRolemasterTriggerRoll(int roll)
+    {
+        return roll.ToString("00");
+    }
+
     private static string BuildModifierBreakdown(string core, int modifier, int total)
     {
         return modifier switch
@@ -1404,7 +1422,7 @@ public sealed class GameService : IGameService
                 .Select(die => die.Roll.ToString())
                 .ToArray();
             if (lowFollowUps.Length > 0)
-                return $"{openEndedInitial.Roll} - ({string.Join(" + ", lowFollowUps)}) | open-ended low";
+                return $"({FormatRolemasterTriggerRoll(openEndedInitial.Roll)}) {string.Join(" ", lowFollowUps.Select(roll => $"-{roll}"))} | open-ended low";
 
             return $"{openEndedInitial.Roll} | open-ended";
         }