diff --git a/src/BannedSymbols.BannedApiAnalyzers.txt b/src/BannedSymbols.BannedApiAnalyzers.txt
index 3de391805c..2a8d9aca85 100644
--- a/src/BannedSymbols.BannedApiAnalyzers.txt
+++ b/src/BannedSymbols.BannedApiAnalyzers.txt
@@ -9,4 +9,6 @@ M:System.Convert.ToSingle(System.String);use float.{Try,}Parse
 M:System.Convert.ToUInt16(System.String);use ushort.{Try,}Parse
 M:System.Convert.ToUInt32(System.String);use uint.{Try,}Parse
 M:System.Convert.ToUInt64(System.String);use ulong.{Try,}Parse
+M:System.Diagnostics.Debug.Assert(System.Boolean);include a unique message
+M:System.Diagnostics.Trace.Assert(System.Boolean);include a unique message
 M:System.Windows.Forms.Control.Focus;use Activate for Forms, or Select otherwise
diff --git a/src/BizHawk.Bizware.Graphics/BitmapBuffer.cs b/src/BizHawk.Bizware.Graphics/BitmapBuffer.cs
index 8bcb1ce2fb..0352fb4502 100644
--- a/src/BizHawk.Bizware.Graphics/BitmapBuffer.cs
+++ b/src/BizHawk.Bizware.Graphics/BitmapBuffer.cs
@@ -65,7 +65,7 @@ namespace BizHawk.Bizware.Graphics
 
 		public void UnlockBits(BitmapData bmpd)
 		{
-			Debug.Assert(CurrLock == bmpd);
+			Debug.Assert(CurrLock == bmpd, "must pass in the same object obtained from " + nameof(LockBits));
 
 			if (WrappedBitmap != null)
 			{
diff --git a/src/BizHawk.Client.Common/DisplayManager/FilterManager.cs b/src/BizHawk.Client.Common/DisplayManager/FilterManager.cs
index e0ab617a9f..f1e533f095 100644
--- a/src/BizHawk.Client.Common/DisplayManager/FilterManager.cs
+++ b/src/BizHawk.Client.Common/DisplayManager/FilterManager.cs
@@ -285,7 +285,7 @@ namespace BizHawk.Client.Common.FilterManager
 					if (ps.Type == ProgramStepType.NewTarget)
 					{
 						var size = (Size)ps.Args;
-						Debug.Assert(size == outsize);
+						Debug.Assert(size == outsize, "size of last " + nameof(ProgramStepType.NewTarget) + " was set wrong");
 						Program[i] = new(ProgramStepType.FinalTarget, size, ps.Comment);
 						break;
 					}
diff --git a/src/BizHawk.Client.Common/fwmanager/FirmwareManager.cs b/src/BizHawk.Client.Common/fwmanager/FirmwareManager.cs
index ca9a229f60..ebbb69bf6b 100644
--- a/src/BizHawk.Client.Common/fwmanager/FirmwareManager.cs
+++ b/src/BizHawk.Client.Common/fwmanager/FirmwareManager.cs
@@ -1,7 +1,6 @@
 #nullable enable
 
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.IO;
 using System.Linq;
 
@@ -27,7 +26,7 @@ namespace BizHawk.Client.Common
 		{
 			var @base = File.ReadAllBytes(baseFilename);
 			var (patched, actualHash) = PerformPatchInMemory(@base, in patchOption);
-			Trace.Assert(actualHash == patchOption.TargetHash);
+			if (actualHash != patchOption.TargetHash) throw new InvalidOperationException("patch produced incorrect output");
 			var patchedParentDir = Path.Combine(pathEntries[PathEntryCollection.GLOBAL, "Temp Files"].Path, "AutopatchedFirmware");
 			Directory.CreateDirectory(patchedParentDir);
 			var ff = FirmwareDatabase.FirmwareFilesByHash[patchOption.TargetHash];
diff --git a/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs b/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs
index e0d34f5049..ea1a2aa48b 100644
--- a/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs
+++ b/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs
@@ -821,13 +821,13 @@ namespace BizHawk.Client.EmuHawk
 
 		private bool IsVisible(int index)
 		{
-			Debug.Assert(FirstVisibleRow < LastFullyVisibleRow);
+			Debug.Assert(FirstVisibleRow < LastFullyVisibleRow, "rows out of order?");
 			return FirstVisibleRow <= index && index <= LastFullyVisibleRow;
 		}
 
 		public bool IsPartiallyVisible(int index)
 		{
-			Debug.Assert(FirstVisibleRow < LastVisibleRow);
+			Debug.Assert(FirstVisibleRow < LastVisibleRow, "rows out of order?");
 			return FirstVisibleRow <= index && index <= LastVisibleRow;
 		}
 
diff --git a/src/BizHawk.Client.EmuHawk/DisplayManager/DisplayManager.cs b/src/BizHawk.Client.EmuHawk/DisplayManager/DisplayManager.cs
index 69eeea9b3a..7828de339b 100644
--- a/src/BizHawk.Client.EmuHawk/DisplayManager/DisplayManager.cs
+++ b/src/BizHawk.Client.EmuHawk/DisplayManager/DisplayManager.cs
@@ -110,7 +110,7 @@ namespace BizHawk.Client.EmuHawk
 				return;
 			}
 
-			Debug.Assert(inFinalTarget);
+			Debug.Assert(inFinalTarget, "not in final target?");
 
 			// present and conclude drawing
 			_graphicsControl.SwapBuffers();
diff --git a/src/BizHawk.Client.EmuHawk/tools/SNES/SNESGraphicsDebugger.cs b/src/BizHawk.Client.EmuHawk/tools/SNES/SNESGraphicsDebugger.cs
index 71858075f2..89cf744d0b 100644
--- a/src/BizHawk.Client.EmuHawk/tools/SNES/SNESGraphicsDebugger.cs
+++ b/src/BizHawk.Client.EmuHawk/tools/SNES/SNESGraphicsDebugger.cs
@@ -24,6 +24,7 @@
 
 using System.Collections;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Drawing;
 using System.Drawing.Imaging;
 using System.Windows.Forms;
@@ -459,7 +460,7 @@ namespace BizHawk.Client.EmuHawk
 						dims.Height = dims.Width = Math.Max(dims.Width, dims.Height);
 						allocate(dims.Width, dims.Height);
 						numPixels = dims.Width * dims.Height;
-						System.Diagnostics.Debug.Assert(stride / 4 == dims.Width);
+						Debug.Assert(dims.Width * 4 == stride, "line is not `width` pixels at 32bpp?");
 
 						map = gd.FetchTilemap(bg.ScreenAddr, bg.ScreenSize);
 						int paletteStart = 0;
diff --git a/src/BizHawk.Common/BPSPatcher.cs b/src/BizHawk.Common/BPSPatcher.cs
index 5f2c9aa13d..68b0c50f8f 100644
--- a/src/BizHawk.Common/BPSPatcher.cs
+++ b/src/BizHawk.Common/BPSPatcher.cs
@@ -148,7 +148,7 @@ namespace BizHawk.Common
 						if (size is 0)
 						{
 							var rleSize = (data[i++] * 0x100) | data[i++];
-							Debug.Assert(rleSize is not 0);
+							Debug.Assert(rleSize is not 0, "may not run-length-encode nothing");
 							records.Add((i, targetOffset, rleSize, true));
 							i++;
 						}
diff --git a/src/BizHawk.Common/Bit.cs b/src/BizHawk.Common/Bit.cs
index fb1aff55ef..51da3672cc 100644
--- a/src/BizHawk.Common/Bit.cs
+++ b/src/BizHawk.Common/Bit.cs
@@ -14,19 +14,19 @@ namespace BizHawk.Common
 		
 		public static implicit operator Bit(int rhs)
 		{
-			Debug.Assert((rhs & ~1) == 0);
+			Debug.Assert((rhs & ~1) is 0, "higher bits can't be used");
 			return new Bit((uint)rhs);
 		}
 
 		public static implicit operator Bit(uint rhs)
 		{
-			Debug.Assert((rhs & ~1) == 0);
+			Debug.Assert((rhs & ~1) is 0, "higher bits can't be used");
 			return new Bit(rhs);
 		}
 
 		public static implicit operator Bit(byte rhs)
 		{
-			Debug.Assert((rhs & ~1) == 0);
+			Debug.Assert((rhs & ~1) is 0, "higher bits can't be used");
 			return new Bit(rhs);
 		}
 
diff --git a/src/BizHawk.Common/EndiannessUtils.cs b/src/BizHawk.Common/EndiannessUtils.cs
index e0322bdec0..af30ffc899 100644
--- a/src/BizHawk.Common/EndiannessUtils.cs
+++ b/src/BizHawk.Common/EndiannessUtils.cs
@@ -9,7 +9,7 @@ namespace BizHawk.Common
 		{
 #if true //TODO benchmark (both methods work correctly); also there is another method involving shifting the (output copy of the) array over by 1 byte then manually writing every second byte
 			var l = a.Length;
-			Debug.Assert(l % 2 == 0);
+			Debug.Assert(l % 2 is 0, "octets must be in pairs");
 			fixed (byte* p = &a[0]) for (var i = 0; i < l; i += 2)
 			{
 				var b = p[i];
@@ -17,7 +17,7 @@ namespace BizHawk.Common
 				p[i + 1] = b;
 			}
 #else
-			Debug.Assert(a.Length % 2 == 0);
+			Debug.Assert(a.Length % 2 is 0, "octets must be in pairs");
 			var shorts = MemoryMarshal.Cast<byte, ushort>(a);
 			for (var i = 0; i < shorts.Length; i++) shorts[i] = BinaryPrimitives.ReverseEndianness(shorts[i]);
 #endif
@@ -28,7 +28,7 @@ namespace BizHawk.Common
 		{
 #if true //TODO benchmark (both methods work correctly)
 			var l = a.Length;
-			Debug.Assert(l % 4 == 0);
+			Debug.Assert(l % 4 is 0, "octets must be in groups of 4");
 			fixed (byte* p = &a[0]) for (var i = 0; i < l; i += 4)
 			{
 				var b = p[i];
@@ -39,7 +39,7 @@ namespace BizHawk.Common
 				p[i + 2] = b;
 			}
 #else
-			Debug.Assert(a.Length % 4 == 0);
+			Debug.Assert(a.Length % 4 is 0, "octets must be in groups of 4");
 			var ints = MemoryMarshal.Cast<byte, uint>(a);
 			for (var i = 0; i < ints.Length; i++) ints[i] = BinaryPrimitives.ReverseEndianness(ints[i]);
 #endif
diff --git a/src/BizHawk.Common/Extensions/CollectionExtensions.cs b/src/BizHawk.Common/Extensions/CollectionExtensions.cs
index 8159f09ab7..288279fcb0 100644
--- a/src/BizHawk.Common/Extensions/CollectionExtensions.cs
+++ b/src/BizHawk.Common/Extensions/CollectionExtensions.cs
@@ -133,7 +133,7 @@ namespace BizHawk.Common.CollectionExtensions
 			if (a.Length is 0) return b;
 			var combined = new T[a.Length + b.Length];
 			var returned = ((ReadOnlySpan<T>) a).ConcatArray(b, combined);
-			Debug.Assert(returned == combined);
+			Debug.Assert(returned == combined, "expecting return value to cover all of combined since the whole thing was written to");
 			return combined;
 		}
 
diff --git a/src/BizHawk.Common/Util.cs b/src/BizHawk.Common/Util.cs
index 7b37bf9427..7a74dfd646 100644
--- a/src/BizHawk.Common/Util.cs
+++ b/src/BizHawk.Common/Util.cs
@@ -54,7 +54,7 @@ namespace BizHawk.Common
 			if (tmp[0] != 0x1F || tmp[1] != 0x8B) throw new InvalidOperationException("GZIP header not present");
 			src.Seek(-4, SeekOrigin.End);
 			var bytesRead = src.Read(tmp, offset: 0, count: tmp.Length);
-			Debug.Assert(bytesRead == tmp.Length);
+			Debug.Assert(bytesRead == tmp.Length, "failed to read tail");
 			src.Seek(0, SeekOrigin.Begin);
 			using var gs = new GZipStream(src, CompressionMode.Decompress, true);
 			var data = new byte[BitConverter.ToInt32(tmp, 0)];
diff --git a/src/BizHawk.Common/checksums/MD5Checksum.cs b/src/BizHawk.Common/checksums/MD5Checksum.cs
index ae22a96cf4..1fbca25002 100644
--- a/src/BizHawk.Common/checksums/MD5Checksum.cs
+++ b/src/BizHawk.Common/checksums/MD5Checksum.cs
@@ -31,7 +31,7 @@ namespace BizHawk.Common
 				if (_md5Impl == null)
 				{
 					_md5Impl = MD5.Create();
-					Debug.Assert(_md5Impl.CanReuseTransform && _md5Impl.HashSize is EXPECTED_LENGTH);
+					Debug.Assert(_md5Impl.CanReuseTransform && _md5Impl.HashSize is EXPECTED_LENGTH, "nonstandard implementation?");
 				}
 				return _md5Impl;
 			}
diff --git a/src/BizHawk.Common/checksums/SHA1Checksum.cs b/src/BizHawk.Common/checksums/SHA1Checksum.cs
index 0abe8f4b1a..74c1fc5c88 100644
--- a/src/BizHawk.Common/checksums/SHA1Checksum.cs
+++ b/src/BizHawk.Common/checksums/SHA1Checksum.cs
@@ -49,7 +49,7 @@ namespace BizHawk.Common
 				if (_sha1Impl == null)
 				{
 					_sha1Impl = SHA1.Create();
-					Debug.Assert(_sha1Impl.CanReuseTransform && _sha1Impl.HashSize is EXPECTED_LENGTH);
+					Debug.Assert(_sha1Impl.CanReuseTransform && _sha1Impl.HashSize is EXPECTED_LENGTH, "nonstandard implementation?");
 				}
 				return _sha1Impl;
 			}
diff --git a/src/BizHawk.Common/checksums/SHA256Checksum.cs b/src/BizHawk.Common/checksums/SHA256Checksum.cs
index c8e5d58768..b999e02c48 100644
--- a/src/BizHawk.Common/checksums/SHA256Checksum.cs
+++ b/src/BizHawk.Common/checksums/SHA256Checksum.cs
@@ -31,7 +31,7 @@ namespace BizHawk.Common
 				if (_sha256Impl == null)
 				{
 					_sha256Impl = SHA256.Create();
-					Debug.Assert(_sha256Impl.CanReuseTransform && _sha256Impl.HashSize is EXPECTED_LENGTH);
+					Debug.Assert(_sha256Impl.CanReuseTransform && _sha256Impl.HashSize is EXPECTED_LENGTH, "nonstandard implementation?");
 				}
 				return _sha256Impl;
 			}
diff --git a/src/BizHawk.Emulation.Common/Base Implementations/MemoryCallbackSystem.cs b/src/BizHawk.Emulation.Common/Base Implementations/MemoryCallbackSystem.cs
index 37bca8e70c..d9af496981 100644
--- a/src/BizHawk.Emulation.Common/Base Implementations/MemoryCallbackSystem.cs	
+++ b/src/BizHawk.Emulation.Common/Base Implementations/MemoryCallbackSystem.cs	
@@ -276,7 +276,7 @@ namespace BizHawk.Emulation.Common
 
 		private void RemoveAtInternal(int index)
 		{
-			Debug.Assert(_modifyInProgress);
+			Debug.Assert(_modifyInProgress, "unexpected collection mutation state");
 			CopyIfRequired();
 
 			var removedItem = _items[index];
@@ -357,7 +357,7 @@ namespace BizHawk.Emulation.Common
 		private void EndCopyOnWrite()
 		{
 			_copyOnWriteRequired--;
-			Debug.Assert(_copyOnWriteRequired >= 0);
+			Debug.Assert(_copyOnWriteRequired >= 0, "unexpected CoW state");
 		}
 
 		public Enumerator GetEnumerator()
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IEmulator.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IEmulator.cs
index f6b1ed3348..139e7b279d 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IEmulator.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IEmulator.cs
@@ -49,7 +49,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 					{
 						// target number of samples to emit: length of 1 frame minus whatever overflow
 						samplesEmitted = TICKSINFRAME - frameOverflow;
-						Debug.Assert(samplesEmitted * 2 <= _soundbuff.Length);
+						Debug.Assert(samplesEmitted * 2 <= _soundbuff.Length, "buffer capacity exceeded");
 						if (LibGambatte.gambatte_runfor(GambatteState, FrameBuffer, 160, _soundbuff, ref samplesEmitted) > 0)
 						{
 							Array.Copy(FrameBuffer, VideoBuffer, FrameBuffer.Length);
@@ -90,7 +90,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 							inputFrameLengthInt = TICKSINFRAME;
 						}
 						samplesEmitted = inputFrameLengthInt - frameOverflow;
-						Debug.Assert(samplesEmitted * 2 <= _soundbuff.Length);
+						Debug.Assert(samplesEmitted * 2 <= _soundbuff.Length, "buffer capacity exceeded");
 						if (LibGambatte.gambatte_runfor(GambatteState, FrameBuffer, 160, _soundbuff, ref samplesEmitted) > 0)
 						{
 							Array.Copy(FrameBuffer, VideoBuffer, FrameBuffer.Length);
diff --git a/src/BizHawk.Emulation.DiscSystem/DiscFormats/Blobs/Blob_ECM.cs b/src/BizHawk.Emulation.DiscSystem/DiscFormats/Blobs/Blob_ECM.cs
index e56b4bfa06..f8cf244839 100644
--- a/src/BizHawk.Emulation.DiscSystem/DiscFormats/Blobs/Blob_ECM.cs
+++ b/src/BizHawk.Emulation.DiscSystem/DiscFormats/Blobs/Blob_ECM.cs
@@ -5,6 +5,7 @@
 
 using System.IO;
 using System.Collections.Generic;
+using System.Diagnostics;
 
 using BizHawk.Common.CollectionExtensions;
 using BizHawk.Common.NumberExtensions;
@@ -171,7 +172,7 @@ namespace BizHawk.Emulation.DiscSystem
 
 			//Console.WriteLine("binary searched"); //use this to check for mistaken LastReadIndex logic resulting in binary searches during sequential access
 			var listIndex = Index.LowerBoundBinarySearch(idx => idx.LogicalOffset, offset);
-			System.Diagnostics.Debug.Assert(listIndex < Index.Count);
+			Debug.Assert(listIndex < Index.Count, "insertion point may not be after end");
 			//Console.WriteLine("byte_pos {0:X8} using index #{1} at offset {2:X8}", offset, listIndex, Index[listIndex].LogicalOffset);
 
 			return listIndex;
diff --git a/src/BizHawk.Emulation.DiscSystem/DiscoHawkLogic/ECMTest.cs b/src/BizHawk.Emulation.DiscSystem/DiscoHawkLogic/ECMTest.cs
index 93d5051c10..0027a5738c 100644
--- a/src/BizHawk.Emulation.DiscSystem/DiscoHawkLogic/ECMTest.cs
+++ b/src/BizHawk.Emulation.DiscSystem/DiscoHawkLogic/ECMTest.cs
@@ -81,10 +81,9 @@ namespace BizHawk.Emulation.DiscSystem
 //					plaindisc.ReadLBA_2352_Flat(item.Item1, chunkbuf_corlet, 0, item.Item2); // API has changed
 //					ecmdisc.ReadLBA_2352_Flat(item.Item1, chunkbuf_mine, 0, item.Item2); // API has changed
 					for (int i = 0; i < item.Item2; i++)
-						if (chunkbuf_corlet[i] != chunkbuf_mine[i])
-						{
-							Debug.Assert(false);
-						}
+					{
+						Debug.Assert(chunkbuf_corlet[i] == chunkbuf_mine[i], $"buffers differ at [{t}; {i}]");
+					}
 				}
 			}
 		}