From cada74c7ac11139955ab487439a184b4f6717a9a Mon Sep 17 00:00:00 2001 From: Frank Tovar Date: Sun, 15 Mar 2026 02:47:10 +0100 Subject: [PATCH] Add rules-aware lookup dice rolling --- docs/player_gm_ux_redesign_plan.md | 6 +- .../Components/Pages/Api.razor | 8 +- .../Components/Pages/Home.razor | 157 +++++++++++++++++- .../Data/RolemasterDbInitializer.cs | 2 + .../Data/RolemasterDbSchemaUpgrader.cs | 64 +++++++ .../Data/RolemasterSeedData.cs | 32 ++++ src/RolemasterDb.App/Domain/AttackTable.cs | 2 + .../Features/LookupContracts.cs | 9 +- .../Features/LookupRollResult.cs | 10 ++ .../Features/LookupService.cs | 7 +- .../Features/RolemasterRoller.cs | 46 +++++ src/RolemasterDb.App/wwwroot/app.css | 33 ++++ .../LookupRollingTests.cs | 150 +++++++++++++++++ .../SequenceRandom.cs | 22 +++ 14 files changed, 540 insertions(+), 8 deletions(-) create mode 100644 src/RolemasterDb.App/Features/LookupRollResult.cs create mode 100644 src/RolemasterDb.App/Features/RolemasterRoller.cs create mode 100644 src/RolemasterDb.ImportTool.Tests/LookupRollingTests.cs create mode 100644 src/RolemasterDb.ImportTool.Tests/SequenceRandom.cs diff --git a/docs/player_gm_ux_redesign_plan.md b/docs/player_gm_ux_redesign_plan.md index 3d6d67f..2f8ccb6 100644 --- a/docs/player_gm_ux_redesign_plan.md +++ b/docs/player_gm_ux_redesign_plan.md @@ -514,6 +514,10 @@ These changes are real and complete, but they are no longer the active roadmap b ### Phase 1: Complete live lookup flow ergonomics +Status: + +- implemented in the web app on March 15, 2026 + Scope: - add dice buttons to the attack and direct critical lookup inputs @@ -622,4 +626,4 @@ Mitigation: ## Recommended Next Step -Implement the new Phase 1 and Phase 2 first. Dice-button support and the compact inline popup editor close the most visible gaps in the detailed acceptance checklist and should be completed before the override and compare workflow phases. +Implement the new Phase 2 next. The compact inline popup editor is now the most visible remaining UX gap after the lookup flow ergonomics pass. diff --git a/src/RolemasterDb.App/Components/Pages/Api.razor b/src/RolemasterDb.App/Components/Pages/Api.razor index b773958..12868c9 100644 --- a/src/RolemasterDb.App/Components/Pages/Api.razor +++ b/src/RolemasterDb.App/Components/Pages/Api.razor @@ -8,7 +8,13 @@

GET /api/reference-data

{
   "attackTables": [
-    { "key": "broadsword", "label": "Broadsword" }
+    {
+      "key": "broadsword",
+      "label": "Broadsword",
+      "attackKind": "melee",
+      "fumbleMinRoll": 1,
+      "fumbleMaxRoll": 2
+    }
   ],
   "criticalTables": [
     {
diff --git a/src/RolemasterDb.App/Components/Pages/Home.razor b/src/RolemasterDb.App/Components/Pages/Home.razor
index 052b8d7..37d3d05 100644
--- a/src/RolemasterDb.App/Components/Pages/Home.razor
+++ b/src/RolemasterDb.App/Components/Pages/Home.razor
@@ -1,5 +1,6 @@
 @page "/"
 @rendermode InteractiveServer
+@using System
 @inject LookupService LookupService
 
 Lookup Desk
@@ -21,7 +22,7 @@ else
                 

                     

                         
-                        
                             @foreach (var attackTable in referenceData.AttackTables)
                             {
                                 
@@ -41,12 +42,34 @@ else
 
                     

                         
-                        
+                        

+                            
+                            
+                        

+                        @if (SelectedAttackTable is { FumbleMinRoll: int attackFumbleMin, FumbleMaxRoll: int attackFumbleMax })
+                        {
+                            
Fumble range: @FormatRange(attackFumbleMin, attackFumbleMax)

+                        }
+                        @if (!string.IsNullOrWhiteSpace(attackRollSummary))
+                        {
+                            
@attackRollSummary

+                        }
+                        @if (!string.IsNullOrWhiteSpace(attackFumbleMessage))
+                        {
+                            
@attackFumbleMessage

+                        }
                     

 
                     

                         
-                        
+                        

+                            
+                            
+                        

+                        @if (!string.IsNullOrWhiteSpace(attackCriticalRollSummary))
+                        {
+                            
@attackCriticalRollSummary

+                        }
                     

                 

 
@@ -140,7 +163,14 @@ else
 
                     

                         
-                        
+                        

+                            
+                            
+                        

+                        @if (!string.IsNullOrWhiteSpace(directCriticalRollSummary))
+                        {
+                            
@directCriticalRollSummary

+                        }
                     

                 

 
@@ -172,6 +202,13 @@ else
     private CriticalLookupResponse? criticalResult;
     private string? attackError;
     private string? criticalError;
+    private string? attackRollSummary;
+    private string? attackCriticalRollSummary;
+    private string? directCriticalRollSummary;
+    private string? attackFumbleMessage;
+
+    private AttackTableReference? SelectedAttackTable =>
+        referenceData?.AttackTables.FirstOrDefault(table => table.Key == attackInput.AttackTable);
 
     private CriticalTableReference? SelectedCriticalTable =>
         referenceData?.CriticalTables.FirstOrDefault(table => table.Key == criticalInput.CriticalType);
@@ -193,6 +230,12 @@ else
     {
         attackError = null;
         attackResult = null;
+        attackFumbleMessage = BuildAttackFumbleMessage(attackInput.AttackRoll);
+
+        if (!string.IsNullOrWhiteSpace(attackFumbleMessage))
+        {
+            return;
+        }
 
         if (!int.TryParse(attackInput.CriticalRollText, out var criticalRoll) && !string.IsNullOrWhiteSpace(attackInput.CriticalRollText))
         {
@@ -244,8 +287,114 @@ else
         criticalInput.Group = table?.Groups.FirstOrDefault()?.Key ?? string.Empty;
         criticalResult = null;
         criticalError = null;
+        directCriticalRollSummary = null;
     }
 
+    private void HandleAttackTableChanged(ChangeEventArgs args)
+    {
+        attackInput.AttackTable = args.Value?.ToString() ?? string.Empty;
+        attackResult = null;
+        attackError = null;
+        attackCriticalRollSummary = null;
+        RefreshAttackRollState();
+    }
+
+    private void RollAttack()
+    {
+        var result = RolemasterRoller.RollAttack(Random.Shared);
+        attackInput.AttackRoll = result.Total;
+        attackRollSummary = BuildRollSummary(result, "Attack");
+        attackCriticalRollSummary = null;
+        attackResult = null;
+        attackError = null;
+        RefreshAttackRollState();
+    }
+
+    private async Task RollAttackCriticalAsync()
+    {
+        attackError = null;
+        attackCriticalRollSummary = null;
+        attackFumbleMessage = BuildAttackFumbleMessage(attackInput.AttackRoll);
+
+        if (!string.IsNullOrWhiteSpace(attackFumbleMessage))
+        {
+            attackCriticalRollSummary = "No critical roll is needed because the current attack roll is a fumble.";
+            return;
+        }
+
+        CriticalTableReference? criticalTable = null;
+        var pendingAttack = await LookupService.LookupAttackAsync(new AttackLookupRequest(
+            attackInput.AttackTable,
+            attackInput.ArmorType,
+            attackInput.AttackRoll,
+            null));
+
+        if (!string.IsNullOrWhiteSpace(pendingAttack?.CriticalType))
+        {
+            criticalTable = referenceData?.CriticalTables.FirstOrDefault(item =>
+                string.Equals(item.Key, pendingAttack.CriticalType, StringComparison.Ordinal));
+        }
+
+        var result = RolemasterRoller.RollCritical(Random.Shared, criticalTable);
+        attackInput.CriticalRollText = result.Total.ToString();
+        attackCriticalRollSummary = BuildCriticalRollSummary(result, criticalTable);
+        attackResult = null;
+    }
+
+    private void RollDirectCritical()
+    {
+        var result = RolemasterRoller.RollCritical(Random.Shared, SelectedCriticalTable);
+        criticalInput.Roll = result.Total;
+        directCriticalRollSummary = BuildCriticalRollSummary(result, SelectedCriticalTable);
+        criticalResult = null;
+        criticalError = null;
+    }
+
+    private void RefreshAttackRollState()
+    {
+        attackFumbleMessage = BuildAttackFumbleMessage(attackInput.AttackRoll);
+    }
+
+    private string? BuildAttackFumbleMessage(int attackRoll)
+    {
+        if (SelectedAttackTable is not { FumbleMinRoll: int fumbleMinRoll, FumbleMaxRoll: int fumbleMaxRoll } ||
+            attackRoll < fumbleMinRoll ||
+            attackRoll > fumbleMaxRoll)
+        {
+            return null;
+        }
+
+        return $"{SelectedAttackTable.Label} fumble on {FormatRange(fumbleMinRoll, fumbleMaxRoll)}. Do not run a normal attack lookup.";
+    }
+
+    private static string BuildRollSummary(LookupRollResult result, string label)
+    {
+        if (!result.IsOpenEnded)
+        {
+            return $"{label} roll: {result.Total}.";
+        }
+
+        return $"{label} roll: {string.Join(" + ", result.Rolls)} = {result.Total}.";
+    }
+
+    private static string BuildCriticalRollSummary(
+        LookupRollResult result,
+        CriticalTableReference? criticalTable)
+    {
+        var summary = BuildRollSummary(result, "Critical");
+        if (criticalTable is null)
+        {
+            return $"{summary} Standard 1-100 roll used because no critical table is currently resolved from the attack result.";
+        }
+
+        return RolemasterRoller.AllowsOpenEndedCritical(criticalTable)
+            ? $"{summary} {criticalTable.Label} uses open-ended rolls."
+            : $"{summary} {criticalTable.Label} is capped at 1-100.";
+    }
+
+    private static string FormatRange(int minRoll, int maxRoll) =>
+        $"{minRoll:00}-{maxRoll:00}";
+
     private sealed class AttackLookupForm
     {
         public string AttackTable { get; set; } = string.Empty;
diff --git a/src/RolemasterDb.App/Data/RolemasterDbInitializer.cs b/src/RolemasterDb.App/Data/RolemasterDbInitializer.cs
index aa3ef6c..3a799d8 100644
--- a/src/RolemasterDb.App/Data/RolemasterDbInitializer.cs
+++ b/src/RolemasterDb.App/Data/RolemasterDbInitializer.cs
@@ -12,9 +12,11 @@ public static class RolemasterDbInitializer
 
         await dbContext.Database.EnsureCreatedAsync(cancellationToken);
         await RolemasterDbSchemaUpgrader.EnsureLatestAsync(dbContext, cancellationToken);
+        RolemasterSeedData.BackfillAttackTableMetadata(dbContext);
 
         if (await dbContext.AttackTables.AnyAsync(cancellationToken))
         {
+            await dbContext.SaveChangesAsync(cancellationToken);
             return;
         }
 
diff --git a/src/RolemasterDb.App/Data/RolemasterDbSchemaUpgrader.cs b/src/RolemasterDb.App/Data/RolemasterDbSchemaUpgrader.cs
index b26f552..096de14 100644
--- a/src/RolemasterDb.App/Data/RolemasterDbSchemaUpgrader.cs
+++ b/src/RolemasterDb.App/Data/RolemasterDbSchemaUpgrader.cs
@@ -1,3 +1,4 @@
+using System;
 using Microsoft.EntityFrameworkCore;
 
 namespace RolemasterDb.App.Data;
@@ -6,6 +7,8 @@ public static class RolemasterDbSchemaUpgrader
 {
     public static async Task EnsureLatestAsync(RolemasterDbContext dbContext, CancellationToken cancellationToken = default)
     {
+        await EnsureAttackTableFumbleColumnsAsync(dbContext, cancellationToken);
+
         await dbContext.Database.ExecuteSqlRawAsync(
             """
             CREATE TABLE IF NOT EXISTS "CriticalBranches" (
@@ -87,4 +90,65 @@ public static class RolemasterDbSchemaUpgrader
             """,
             cancellationToken);
     }
+
+    private static async Task EnsureAttackTableFumbleColumnsAsync(RolemasterDbContext dbContext, CancellationToken cancellationToken)
+    {
+        if (!await ColumnExistsAsync(dbContext, "AttackTables", "FumbleMinRoll", cancellationToken))
+        {
+            await dbContext.Database.ExecuteSqlRawAsync(
+                """
+                ALTER TABLE "AttackTables"
+                ADD COLUMN "FumbleMinRoll" INTEGER NULL;
+                """,
+                cancellationToken);
+        }
+
+        if (!await ColumnExistsAsync(dbContext, "AttackTables", "FumbleMaxRoll", cancellationToken))
+        {
+            await dbContext.Database.ExecuteSqlRawAsync(
+                """
+                ALTER TABLE "AttackTables"
+                ADD COLUMN "FumbleMaxRoll" INTEGER NULL;
+                """,
+                cancellationToken);
+        }
+    }
+
+    private static async Task ColumnExistsAsync(
+        RolemasterDbContext dbContext,
+        string tableName,
+        string columnName,
+        CancellationToken cancellationToken)
+    {
+        var connection = dbContext.Database.GetDbConnection();
+        var shouldClose = connection.State != System.Data.ConnectionState.Open;
+        if (shouldClose)
+        {
+            await connection.OpenAsync(cancellationToken);
+        }
+
+        try
+        {
+            await using var command = connection.CreateCommand();
+            command.CommandText = $"PRAGMA table_info(\"{tableName}\");";
+
+            await using var reader = await command.ExecuteReaderAsync(cancellationToken);
+            while (await reader.ReadAsync(cancellationToken))
+            {
+                if (string.Equals(reader["name"]?.ToString(), columnName, StringComparison.Ordinal))
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+        finally
+        {
+            if (shouldClose)
+            {
+                await connection.CloseAsync();
+            }
+        }
+    }
 }
diff --git a/src/RolemasterDb.App/Data/RolemasterSeedData.cs b/src/RolemasterDb.App/Data/RolemasterSeedData.cs
index 487f573..fb6f3d2 100644
--- a/src/RolemasterDb.App/Data/RolemasterSeedData.cs
+++ b/src/RolemasterDb.App/Data/RolemasterSeedData.cs
@@ -4,6 +4,13 @@ namespace RolemasterDb.App.Data;
 
 public static class RolemasterSeedData
 {
+    private static readonly IReadOnlyDictionary AttackTableMetadata =
+        new Dictionary(StringComparer.OrdinalIgnoreCase)
+        {
+            ["broadsword"] = (1, 2),
+            ["short_bow"] = (1, 3)
+        };
+
     public static void SeedAttackStarterData(RolemasterDbContext dbContext)
     {
         List armorTypes;
@@ -28,6 +35,27 @@ public static class RolemasterSeedData
         dbContext.AttackTables.AddRange(attackTables);
     }
 
+    public static void BackfillAttackTableMetadata(RolemasterDbContext dbContext)
+    {
+        foreach (var table in dbContext.AttackTables)
+        {
+            if (!AttackTableMetadata.TryGetValue(table.Slug, out var metadata))
+            {
+                continue;
+            }
+
+            if (table.FumbleMinRoll is null)
+            {
+                table.FumbleMinRoll = metadata.FumbleMinRoll;
+            }
+
+            if (table.FumbleMaxRoll is null)
+            {
+                table.FumbleMaxRoll = metadata.FumbleMaxRoll;
+            }
+        }
+    }
+
     private static List CreateArmorTypes() =>
     [
         new ArmorType { Code = "AT1", Label = "AT1 - Robes", SortOrder = 1 },
@@ -44,6 +72,8 @@ public static class RolemasterSeedData
             Slug = "broadsword",
             DisplayName = "Broadsword",
             AttackKind = "melee",
+            FumbleMinRoll = 1,
+            FumbleMaxRoll = 2,
             Notes = "Starter subset with slash criticals to prove the end-to-end lookup flow."
         };
 
@@ -52,6 +82,8 @@ public static class RolemasterSeedData
             Slug = "short_bow",
             DisplayName = "Short Bow",
             AttackKind = "missile",
+            FumbleMinRoll = 1,
+            FumbleMaxRoll = 3,
             Notes = "Starter subset with puncture criticals."
         };
 
diff --git a/src/RolemasterDb.App/Domain/AttackTable.cs b/src/RolemasterDb.App/Domain/AttackTable.cs
index 4f2e07c..c499d20 100644
--- a/src/RolemasterDb.App/Domain/AttackTable.cs
+++ b/src/RolemasterDb.App/Domain/AttackTable.cs
@@ -7,6 +7,8 @@ public sealed class AttackTable
     public string DisplayName { get; set; } = string.Empty;
     public string AttackKind { get; set; } = string.Empty;
     public string? Notes { get; set; }
+    public int? FumbleMinRoll { get; set; }
+    public int? FumbleMaxRoll { get; set; }
     public List RollBands { get; set; } = [];
     public List Results { get; set; } = [];
 }
diff --git a/src/RolemasterDb.App/Features/LookupContracts.cs b/src/RolemasterDb.App/Features/LookupContracts.cs
index f655907..4083375 100644
--- a/src/RolemasterDb.App/Features/LookupContracts.cs
+++ b/src/RolemasterDb.App/Features/LookupContracts.cs
@@ -4,6 +4,13 @@ namespace RolemasterDb.App.Features;
 
 public sealed record LookupOption(string Key, string Label);
 
+public sealed record AttackTableReference(
+    string Key,
+    string Label,
+    string AttackKind,
+    int? FumbleMinRoll,
+    int? FumbleMaxRoll);
+
 public sealed record CriticalColumnReference(
     string Key,
     string Label,
@@ -32,7 +39,7 @@ public sealed record CriticalTableReference(
     IReadOnlyList RollBands);
 
 public sealed record LookupReferenceData(
-    IReadOnlyList AttackTables,
+    IReadOnlyList AttackTables,
     IReadOnlyList ArmorTypes,
     IReadOnlyList CriticalTables);
 
diff --git a/src/RolemasterDb.App/Features/LookupRollResult.cs b/src/RolemasterDb.App/Features/LookupRollResult.cs
new file mode 100644
index 0000000..99fd908
--- /dev/null
+++ b/src/RolemasterDb.App/Features/LookupRollResult.cs
@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+
+namespace RolemasterDb.App.Features;
+
+public sealed record LookupRollResult(
+    int Total,
+    IReadOnlyList Rolls)
+{
+    public bool IsOpenEnded => Rolls.Count > 1;
+}
diff --git a/src/RolemasterDb.App/Features/LookupService.cs b/src/RolemasterDb.App/Features/LookupService.cs
index f726e3f..05333be 100644
--- a/src/RolemasterDb.App/Features/LookupService.cs
+++ b/src/RolemasterDb.App/Features/LookupService.cs
@@ -18,7 +18,12 @@ public sealed class LookupService(IDbContextFactory dbConte
         var attackTables = await dbContext.AttackTables
             .AsNoTracking()
             .OrderBy(item => item.DisplayName)
-            .Select(item => new LookupOption(item.Slug, item.DisplayName))
+            .Select(item => new AttackTableReference(
+                item.Slug,
+                item.DisplayName,
+                item.AttackKind,
+                item.FumbleMinRoll,
+                item.FumbleMaxRoll))
             .ToListAsync(cancellationToken);
 
         var armorTypes = await dbContext.ArmorTypes
diff --git a/src/RolemasterDb.App/Features/RolemasterRoller.cs b/src/RolemasterDb.App/Features/RolemasterRoller.cs
new file mode 100644
index 0000000..413b016
--- /dev/null
+++ b/src/RolemasterDb.App/Features/RolemasterRoller.cs
@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace RolemasterDb.App.Features;
+
+public static class RolemasterRoller
+{
+    public static LookupRollResult RollAttack(Random random) =>
+        RollOpenEndedHigh(random);
+
+    public static LookupRollResult RollCritical(Random random, CriticalTableReference? table) =>
+        AllowsOpenEndedCritical(table)
+            ? RollOpenEndedHigh(random)
+            : RollStandard(random);
+
+    public static bool AllowsOpenEndedCritical(CriticalTableReference? table) =>
+        table is not null &&
+        table.RollBands.Any(item => item.MinRoll > 100 || item.MaxRoll is null || item.MaxRoll > 100);
+
+    public static LookupRollResult RollStandard(Random random)
+    {
+        var roll = random.Next(1, 101);
+        return new LookupRollResult(roll, [roll]);
+    }
+
+    public static LookupRollResult RollOpenEndedHigh(Random random)
+    {
+        var rolls = new List();
+        var total = 0;
+
+        while (true)
+        {
+            var roll = random.Next(1, 101);
+            rolls.Add(roll);
+            total += roll;
+
+            if (roll < 96)
+            {
+                break;
+            }
+        }
+
+        return new LookupRollResult(total, rolls);
+    }
+}
diff --git a/src/RolemasterDb.App/wwwroot/app.css b/src/RolemasterDb.App/wwwroot/app.css
index 4ae9c64..240062d 100644
--- a/src/RolemasterDb.App/wwwroot/app.css
+++ b/src/RolemasterDb.App/wwwroot/app.css
@@ -115,6 +115,16 @@ textarea {
     gap: 0.35rem;
 }
 
+.roll-input-row {
+    display: flex;
+    gap: 0.55rem;
+    align-items: stretch;
+}
+
+.roll-input-row .input-shell {
+    flex: 1 1 auto;
+}
+
 .field-shell label {
     font-size: 0.85rem;
     letter-spacing: 0.08em;
@@ -158,6 +168,29 @@ textarea {
     background: linear-gradient(135deg, #c38a4d, #8f5a2f);
 }
 
+.roll-button {
+    flex: 0 0 auto;
+    min-width: 4.5rem;
+    border-radius: 14px;
+    border: 1px solid rgba(127, 96, 55, 0.18);
+    background: rgba(255, 248, 236, 0.9);
+    color: #6a4b28;
+    padding: 0.8rem 0.95rem;
+}
+
+.roll-button:hover {
+    background: rgba(250, 236, 210, 0.95);
+}
+
+.lookup-roll-note {
+    margin: 0;
+    font-size: 0.88rem;
+}
+
+.lookup-roll-note.is-warning {
+    color: #8d2b1e;
+}
+
 .tag-row {
     display: flex;
     gap: 0.6rem;
diff --git a/src/RolemasterDb.ImportTool.Tests/LookupRollingTests.cs b/src/RolemasterDb.ImportTool.Tests/LookupRollingTests.cs
new file mode 100644
index 0000000..4fe9f9d
--- /dev/null
+++ b/src/RolemasterDb.ImportTool.Tests/LookupRollingTests.cs
@@ -0,0 +1,150 @@
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+
+using RolemasterDb.App.Data;
+using RolemasterDb.App.Features;
+
+namespace RolemasterDb.ImportTool.Tests;
+
+public sealed class LookupRollingTests
+{
+    [Fact]
+    public void Attack_rolls_open_end_on_high_results()
+    {
+        var result = RolemasterRoller.RollAttack(new SequenceRandom(96, 100, 43));
+
+        Assert.Equal(239, result.Total);
+        Assert.Equal([96, 100, 43], result.Rolls);
+        Assert.True(result.IsOpenEnded);
+    }
+
+    [Fact]
+    public void Standard_critical_rolls_are_capped_at_one_hundred()
+    {
+        var table = CreateCriticalTableReference(
+            "slash",
+            "Slash Critical Strike Table",
+            [new CriticalRollBandReference("01-100", 1, 100, 1)]);
+
+        var result = RolemasterRoller.RollCritical(new SequenceRandom(99), table);
+
+        Assert.Equal(99, result.Total);
+        Assert.Equal([99], result.Rolls);
+        Assert.False(result.IsOpenEnded);
+        Assert.False(RolemasterRoller.AllowsOpenEndedCritical(table));
+    }
+
+    [Fact]
+    public void Extended_critical_rolls_use_open_ended_high_rules()
+    {
+        var table = CreateCriticalTableReference(
+            "large_creature",
+            "Large Creature Critical Strike Table",
+            [new CriticalRollBandReference("101+", 101, null, 1)]);
+
+        var result = RolemasterRoller.RollCritical(new SequenceRandom(97, 45), table);
+
+        Assert.Equal(142, result.Total);
+        Assert.Equal([97, 45], result.Rolls);
+        Assert.True(result.IsOpenEnded);
+        Assert.True(RolemasterRoller.AllowsOpenEndedCritical(table));
+    }
+
+    [Fact]
+    public async Task Schema_upgrader_adds_attack_table_fumble_columns()
+    {
+        var databasePath = Path.Combine(Path.GetTempPath(), $"rolemaster-schema-{Guid.NewGuid():N}.db");
+        await using (var connection = new SqliteConnection($"Data Source={databasePath}"))
+        {
+            await connection.OpenAsync();
+
+            await using var command = connection.CreateCommand();
+            command.CommandText =
+                """
+                CREATE TABLE "AttackTables" (
+                    "Id" INTEGER NOT NULL CONSTRAINT "PK_AttackTables" PRIMARY KEY AUTOINCREMENT,
+                    "Slug" TEXT NOT NULL,
+                    "DisplayName" TEXT NOT NULL,
+                    "AttackKind" TEXT NOT NULL,
+                    "Notes" TEXT NULL
+                );
+                """;
+            await command.ExecuteNonQueryAsync();
+        }
+
+        await using (var dbContext = CreateDbContext(databasePath))
+        {
+            await RolemasterDbSchemaUpgrader.EnsureLatestAsync(dbContext);
+        }
+
+        await using var verifyConnection = new SqliteConnection($"Data Source={databasePath}");
+        await verifyConnection.OpenAsync();
+
+        var columns = new List();
+        await using (var command = verifyConnection.CreateCommand())
+        {
+            command.CommandText = "PRAGMA table_info(\"AttackTables\");";
+            await using var reader = await command.ExecuteReaderAsync();
+            while (await reader.ReadAsync())
+            {
+                columns.Add(reader["name"]!.ToString()!);
+            }
+        }
+
+        Assert.Contains("FumbleMinRoll", columns);
+        Assert.Contains("FumbleMaxRoll", columns);
+    }
+
+    [Fact]
+    public async Task Reference_data_includes_attack_table_fumble_ranges()
+    {
+        var databasePath = Path.Combine(Path.GetTempPath(), $"rolemaster-reference-{Guid.NewGuid():N}.db");
+
+        await using (var dbContext = CreateDbContext(databasePath))
+        {
+            await dbContext.Database.EnsureCreatedAsync();
+            await RolemasterDbSchemaUpgrader.EnsureLatestAsync(dbContext);
+            RolemasterSeedData.SeedAttackStarterData(dbContext);
+            await dbContext.SaveChangesAsync();
+        }
+
+        var lookupService = new LookupService(CreateDbContextFactory(databasePath));
+        var referenceData = await lookupService.GetReferenceDataAsync();
+
+        var broadsword = Assert.Single(referenceData.AttackTables, item => item.Key == "broadsword");
+        Assert.Equal(1, broadsword.FumbleMinRoll);
+        Assert.Equal(2, broadsword.FumbleMaxRoll);
+    }
+
+    private static CriticalTableReference CreateCriticalTableReference(
+        string key,
+        string label,
+        IReadOnlyList rollBands) =>
+        new(
+            key,
+            label,
+            "standard",
+            $"{label}.pdf",
+            null,
+            [],
+            [],
+            rollBands);
+
+    private static RolemasterDbContext CreateDbContext(string databasePath)
+    {
+        var options = new DbContextOptionsBuilder()
+            .UseSqlite($"Data Source={databasePath}")
+            .Options;
+
+        return new RolemasterDbContext(options);
+    }
+
+    private static IDbContextFactory CreateDbContextFactory(string databasePath)
+    {
+        var options = new DbContextOptionsBuilder()
+            .UseSqlite($"Data Source={databasePath}")
+            .Options;
+
+        return new TestRolemasterDbContextFactory(options);
+    }
+}
diff --git a/src/RolemasterDb.ImportTool.Tests/SequenceRandom.cs b/src/RolemasterDb.ImportTool.Tests/SequenceRandom.cs
new file mode 100644
index 0000000..30f500f
--- /dev/null
+++ b/src/RolemasterDb.ImportTool.Tests/SequenceRandom.cs
@@ -0,0 +1,22 @@
+namespace RolemasterDb.ImportTool.Tests;
+
+internal sealed class SequenceRandom(params int[] values) : Random
+{
+    private readonly Queue values = new(values);
+
+    public override int Next(int minValue, int maxValue)
+    {
+        if (values.Count == 0)
+        {
+            throw new InvalidOperationException("No queued random values remain.");
+        }
+
+        var value = values.Dequeue();
+        if (value < minValue || value >= maxValue)
+        {
+            throw new InvalidOperationException($"Queued random value {value} is outside the requested range [{minValue}, {maxValue}).");
+        }
+
+        return value;
+    }
+}