diff --git a/game/aabb.go b/game/aabb.go
index dfc510c6..738f3816 100755
--- a/game/aabb.go
+++ b/game/aabb.go
@@ -118,13 +118,13 @@ func BBHasZeroVolume(bb cube.BBox) bool {
 	return bb.Min() == bb.Max()
 }
 
-func ClosestPointInLineToPoint(origin, end mgl32.Vec3, point mgl32.Vec3) mgl32.Vec3 {
-	line := end.Sub(origin)
+func ClosestPointInLineToPoint(start, end, point mgl32.Vec3) mgl32.Vec3 {
+	line := end.Sub(start)
 	if line.LenSqr() <= 1e-4 {
-		return origin
+		return start
 	}
 
-	t := (point.Sub(origin)).Dot(line) / line.LenSqr()
+	t := (point.Sub(start)).Dot(line) / line.LenSqr()
 	// Clamp to stay on the line segment
 	if t < 0 {
 		t = 0
@@ -132,7 +132,7 @@ func ClosestPointInLineToPoint(origin, end mgl32.Vec3, point mgl32.Vec3) mgl32.V
 		t = 1
 	}
 
-	return origin.Add(line.Mul(t))
+	return start.Add(line.Mul(t))
 }
 
 // ClosestPointToBBox returns the shortest point from a given origin to a given bounding box.
@@ -185,17 +185,15 @@ func ClosestPointToBBoxDirectional(origin, startLook, endLook mgl32.Vec3, bb cub
 		point2 = ClosestPointToBBox(point2, bb)
 	}
 
-	if point1 == point2 {
-		if !hit1 {
-			if !hit2 {
-				// Here, there is no possible way that any point between the two rays can intersect with the bounding box.
-				return mgl32.Vec3{}, false
-			}
-			return point2, true
+	if !hit1 && !hit2 {
+		if point1 == point2 || point1.Y() == point2.Y() || (point1.X() == point2.X() && point1.Z() == point2.Z()) {
+			return mgl32.Vec3{}, false
 		}
+	} else if hit1 {
 		return point1, true
+	} else if hit2 {
+		return point2, true
 	}
-
 	possibleBB := cube.Box(point1.X(), point1.Y(), point1.Z(), point2.X(), point2.Y(), point2.Z())
 	return ClosestPointToBBox(origin, possibleBB), true
 }
diff --git a/game/math.go b/game/math.go
index b6898cef..6a757b4c 100755
--- a/game/math.go
+++ b/game/math.go
@@ -54,6 +54,26 @@ func AbsNum[T uint | int | uint8 | int8 | uint16 | int16 | uint32 | int32 | uint
 	return a
 }
 
+// Round will round a number to the nearest integer.
+func Round[T float32 | float64, V uint | int | uint8 | int8 | uint16 | int16 | uint32 | int32 | uint64 | int64](a T) V {
+	baseFloat := a - T(V(a))
+	base := V(a)
+	if baseFloat >= 0.5 {
+		base++
+	}
+	return base
+}
+
+// PrecisionFloor32 floors a number to the given precision.
+func PrecisionFloor32(a float32, precision float32) int {
+	increaseValueAt := float32(1) - precision
+	floorVal := int(a)
+	if a-float32(floorVal) >= increaseValueAt {
+		floorVal++
+	}
+	return floorVal
+}
+
 // AbsInt64 will return the absolute value of an int64.
 func AbsInt64(a int64) int64 {
 	if a < 0 {
diff --git a/player/component/world.go b/player/component/world.go
index 57d4e112..ecd032a2 100644
--- a/player/component/world.go
+++ b/player/component/world.go
@@ -181,7 +181,7 @@ func (c *WorldUpdaterComponent) AttemptItemInteractionWithBlock(pk *packet.Inven
 	}
 
 	heldItem := holding.Item()
-	c.mPlayer.Dbg.Notify(player.DebugModeBlockPlacement, true, "item in hand: %T", heldItem)
+	c.mPlayer.Dbg.Notify(player.DebugModeBlockPlacement, true, "item in hand (slot %d): %T", c.mPlayer.Inventory().HeldSlot(), heldItem)
 	switch heldItem := heldItem.(type) {
 	case *block.Air:
 		// This only happens when Dragonfly is unsure of what the item is (unregistered), so we use the client-authoritative block in hand.
diff --git a/player/detection/register.go b/player/detection/register.go
index 8d4f01c6..2d3073c3 100644
--- a/player/detection/register.go
+++ b/player/detection/register.go
@@ -23,8 +23,14 @@ func Register(p *player.Player) {
 	p.RegisterDetection(New_EditionFakerB(p))
 	p.RegisterDetection(New_EditionFakerC(p))
 
+	// inv move detections
 	p.RegisterDetection(New_InvMoveA(p))
 
+	// scaffold detections
+	p.RegisterDetection(New_ScaffoldA(p))
+	p.RegisterDetection(New_ScaffoldB(p))
+	//p.RegisterDetection(New_ScaffoldC(p))
+
 	//p.RegisterDetection(New_NukerA(p))
 
 	// killaura detections
diff --git a/player/detection/scaffold_b.go b/player/detection/scaffold_b.go
new file mode 100644
index 00000000..6a3e5fd4
--- /dev/null
+++ b/player/detection/scaffold_b.go
@@ -0,0 +1,206 @@
+package detection
+
+import (
+	"github.com/df-mc/dragonfly/server/world"
+	"github.com/ethaniccc/float32-cube/cube"
+	"github.com/go-gl/mathgl/mgl32"
+	"github.com/oomph-ac/oomph/game"
+	"github.com/oomph-ac/oomph/player"
+	"github.com/sandertv/gophertunnel/minecraft/protocol"
+	"github.com/sandertv/gophertunnel/minecraft/protocol/packet"
+)
+
+var (
+	faceNotSet cube.Face = -1
+)
+
+type ScaffoldB struct {
+	mPlayer  *player.Player
+	metadata *player.DetectionMetadata
+
+	initialFace        cube.Face
+	prevSimBlockPos    cube.Pos
+	hasPrevSimBlockPos bool
+}
+
+func New_ScaffoldB(p *player.Player) *ScaffoldB {
+	return &ScaffoldB{
+		mPlayer: p,
+		metadata: &player.DetectionMetadata{
+			FailBuffer: 1.01,
+			MaxBuffer:  1.5,
+
+			MaxViolations: 10,
+		},
+		initialFace: faceNotSet,
+	}
+}
+
+func (d *ScaffoldB) Type() string {
+	return TypeScaffold
+}
+
+func (d *ScaffoldB) SubType() string {
+	return "B"
+}
+
+func (d *ScaffoldB) Description() string {
+	return "Checks if the block face the player is placing against is valid."
+}
+
+func (d *ScaffoldB) Punishable() bool {
+	return true
+}
+
+func (d *ScaffoldB) Metadata() *player.DetectionMetadata {
+	return d.metadata
+}
+
+func (d *ScaffoldB) Detect(pk packet.Packet) {
+	tr, ok := pk.(*packet.InventoryTransaction)
+	if !ok {
+		return
+	}
+
+	dat, ok := tr.TransactionData.(*protocol.UseItemTransactionData)
+	if !ok || dat.ActionType != protocol.UseItemActionClickBlock || !d.mPlayer.VersionInRange(player.GameVersion1_21_20, protocol.CurrentProtocol) {
+		return
+	}
+	inHand := d.mPlayer.Inventory().Holding()
+	if _, isBlock := inHand.Item().(world.Block); !isBlock {
+		return
+	}
+
+	// We have to check this regardless of whether the client predicted the interaction failed or not - otherwise we get false positives when
+	// checking during when the trigger type is of TriggerTypeSimulationTick (player frame).
+	blockFace := cube.Face(dat.BlockFace)
+	if dat.TriggerType == protocol.TriggerTypePlayerInput {
+		d.initialFace = faceNotSet
+		d.hasPrevSimBlockPos = false
+	} else if d.initialFace == faceNotSet && blockFace != cube.FaceUp && blockFace != cube.FaceDown {
+		d.initialFace = blockFace
+	}
+	if dat.ClientPrediction == protocol.ClientPredictionFailure {
+		return
+	}
+
+	blockPos := cube.Pos{int(dat.BlockPosition[0]), int(dat.BlockPosition[1]), int(dat.BlockPosition[2])}
+	if !d.isFaceInteractable(
+		d.mPlayer.Movement().Client().LastPos(),
+		d.mPlayer.Movement().Client().Pos(),
+		blockPos,
+		blockFace,
+		dat.TriggerType == protocol.TriggerTypePlayerInput,
+	) {
+		d.mPlayer.FailDetection(d, nil)
+	} else {
+		d.mPlayer.PassDetection(d, 0.5)
+	}
+	if d.initialFace != faceNotSet && (blockFace == cube.FaceUp || blockFace == cube.FaceDown) {
+		d.initialFace = blockFace
+	}
+}
+
+func (d *ScaffoldB) isFaceInteractable(
+	startPos,
+	endPos mgl32.Vec3,
+	blockPos cube.Pos,
+	targetFace cube.Face,
+	isClientInput bool,
+) bool {
+	interactableFaces := make(map[cube.Face]struct{}, 6)
+	blockX, blockY, blockZ := blockPos[0], blockPos[1], blockPos[2]
+	floorPosStart := cube.PosFromVec3(startPos)
+	floorPosEnd := cube.PosFromVec3(endPos)
+
+	eyeOffset := game.DefaultPlayerHeightOffset
+	if d.mPlayer.Movement().Sneaking() {
+		eyeOffset = game.SneakingPlayerHeightOffset
+	}
+	floorEyeStart := int(startPos[1] + eyeOffset)
+	floorEyeEnd := int(endPos[1] + eyeOffset)
+
+	if !isClientInput {
+		interactableFaces[cube.FaceDown] = struct{}{}
+		interactableFaces[cube.FaceUp] = struct{}{}
+		if d.initialFace != faceNotSet {
+			interactableFaces[d.initialFace] = struct{}{}
+			interactableFaces[d.initialFace.Opposite()] = struct{}{}
+		}
+
+		prevPos := d.prevSimBlockPos
+		d.prevSimBlockPos = blockPos
+		d.hasPrevSimBlockPos = true
+
+		if d.hasPrevSimBlockPos {
+			found := false
+			for iFace := range interactableFaces {
+				if prevPos.Side(iFace) == blockPos {
+					found = true
+					break
+				}
+			}
+			// Simulation placements must be in a chain and not seperated from each other.
+			if !found {
+				d.mPlayer.Log().Debug("scaffold_b (invalid sim placement)", "blockPos", blockPos, "prevSimBlockPos", prevPos, "interactableFaces", interactableFaces)
+				return false
+			}
+		}
+	} else {
+		// Check for the Y-axis faces first.
+		// If floor(eyePos.Y) < blockPos.Y -> the bottom face is interactable.
+		// If floor(eyePos.Y) > blockPos.Y -> the top face is interactable.
+		isBelowBlock := floorEyeStart < blockY || floorEyeEnd < blockY
+		isAboveBlock := floorEyeStart > blockY || floorEyeEnd > blockY
+		isOnBlock := floorPosStart[1] == blockY+1 || floorPosEnd[1] == blockY+1
+		if isBelowBlock {
+			interactableFaces[cube.FaceDown] = struct{}{}
+		}
+		if isAboveBlock {
+			//d.mPlayer.Message("isOnBlock=%t prevY=%f currY=%f", isOnBlock, startPos[1], endPos[1])
+			interactableFaces[cube.FaceUp] = struct{}{}
+			if isOnBlock {
+				startXDelta := game.AbsNum(floorPosStart[0] - blockX)
+				endXDelta := game.AbsNum(floorPosEnd[0] - blockX)
+				if startXDelta == 0 || endXDelta == 0 {
+					interactableFaces[cube.FaceWest] = struct{}{}
+					interactableFaces[cube.FaceEast] = struct{}{}
+				}
+
+				startZDelta := game.AbsNum(floorPosStart[2] - blockZ)
+				endZDelta := game.AbsNum(floorPosEnd[2] - blockZ)
+				if startZDelta == 0 || endZDelta == 0 {
+					interactableFaces[cube.FaceNorth] = struct{}{}
+					interactableFaces[cube.FaceSouth] = struct{}{}
+				}
+			}
+			//fmt.Println(isOnBlock, floorPosStart[1], floorPosEnd[1], blockY)
+		}
+
+		// Check for the X-axis faces.
+		// If floor(eyePos.X) < blockPos.X -> the west face is interactable.
+		// If floor(eyePos.X) > blockPos.X -> the east face is interactable.
+		if floorPosStart[0] < blockX || floorPosEnd[0] < blockX {
+			interactableFaces[cube.FaceWest] = struct{}{}
+		}
+		if floorPosStart[0] > blockX || floorPosEnd[0] > blockX {
+			interactableFaces[cube.FaceEast] = struct{}{}
+		}
+
+		// Check for the Z-axis faces.
+		// If floor(eyePos.Z) < blockPos.Z -> the north face is interactable.
+		// If floor(eyePos.Z) > blockPos.Z -> the south face is interactable.
+		if floorPosStart[2] < blockZ || floorPosEnd[2] < blockZ {
+			interactableFaces[cube.FaceNorth] = struct{}{}
+		}
+		if floorPosStart[2] > blockZ || floorPosEnd[2] > blockZ {
+			interactableFaces[cube.FaceSouth] = struct{}{}
+		}
+	}
+
+	_, interactable := interactableFaces[targetFace]
+	if !interactable {
+		d.mPlayer.Log().Debug("scaffold_b", "blockPos", blockPos, "startPos", startPos, "endPos", endPos, "isClientInput", isClientInput, "targetFace", targetFace, "interactableFaces", interactableFaces)
+	}
+	return interactable
+}