diff --git a/build.sh b/build.sh
index 6cd2aa14f..feffc26d9 100755
--- a/build.sh
+++ b/build.sh
@@ -56,6 +56,11 @@ for arg in "$@"; do
 		BUILD_GEN=1
 		SOMETHING=1
 		;;
+	--win | -w)
+		EXTRA_LD_FLAGS="-s -w"
+		BUILD_GO=1
+		SOMETHING=1
+		;;
 	--help | -h)
 		echo "$0 [options]"
 		echo "  -a, --all    Equivalent to --gen --go --lint --race"
@@ -67,6 +72,7 @@ for arg in "$@"; do
 		echo "  -l, --lint   Run the linters"
 		echo "  -r, --race   Run the tests with race-checking enabled"
 		echo "  -t, --test   Run the tests"
+		echo "  -w, --win    Force Build for Windows"
 		echo "  -h, --help   This help text"
 		exit 0
 		;;
diff --git a/model/gurps/sheet_settings.go b/model/gurps/sheet_settings.go
index bfb7d4561..342bf553f 100644
--- a/model/gurps/sheet_settings.go
+++ b/model/gurps/sheet_settings.go
@@ -54,6 +54,7 @@ type SheetSettingsData struct {
 	ExcludeUnspentPointsFromTotal bool               `json:"exclude_unspent_points_from_total,omitempty"`
 	ShowLiftingSTDamage           bool               `json:"show_lifting_st_damage,omitempty"`
 	ShowIQBasedDamage             bool               `json:"show_iq_based_damage,omitempty"`
+	UseSkillTrees                 bool               `json:"use_skill_trees,omitempty"`
 }
 
 // SheetSettings holds sheet settings.
diff --git a/model/gurps/skill.go b/model/gurps/skill.go
index fd8391054..6accfc7ff 100644
--- a/model/gurps/skill.go
+++ b/model/gurps/skill.go
@@ -525,10 +525,11 @@ func (s *Skill) DefaultSkill() *Skill {
 	if e == nil {
 		return nil
 	}
+	requirePoints := !e.SheetSettings.UseSkillTrees
 	if s.IsTechnique() {
-		return s.BaseSkill(e, s.TechniqueDefault, true)
+		return s.BaseSkill(e, s.TechniqueDefault, requirePoints)
 	}
-	return s.BaseSkill(e, s.DefaultedFrom, true)
+	return s.BaseSkill(e, s.DefaultedFrom, requirePoints)
 }
 
 // HasDefaultTo returns true if the set of possible defaults includes the other skill.
@@ -728,8 +729,13 @@ func (s *Skill) DecrementSkillLevel() {
 func (s *Skill) CalculateLevel(excludes map[string]bool) Level {
 	points := s.AdjustedPoints(nil)
 	if s.IsTechnique() {
-		return CalculateTechniqueLevel(EntityFromNode(s), s.Replacements, s.NameWithReplacements(),
-			s.SpecializationWithReplacements(), s.Tags, s.TechniqueDefault, s.Difficulty.Difficulty, points, true,
+		e := EntityFromNode(s)
+		requirePoints := true
+		if e != nil {
+			requirePoints = !e.SheetSettings.UseSkillTrees
+		}
+		return CalculateTechniqueLevel(e, s.Replacements, s.NameWithReplacements(),
+			s.SpecializationWithReplacements(), s.Tags, s.TechniqueDefault, s.Difficulty.Difficulty, points, requirePoints,
 			s.TechniqueLimitModifier, excludes)
 	}
 	return CalculateSkillLevel(EntityFromNode(s), s.NameWithReplacements(), s.SpecializationWithReplacements(), s.Tags,
@@ -826,7 +832,7 @@ func CalculateTechniqueLevel(e *Entity, replacements map[string]string, name, sp
 			}
 		} else {
 			// Take the modifier back out, as we wanted the base, not the final value.
-			level = def.SkillLevelFast(e, replacements, true, nil, false) - def.Modifier
+			level = def.SkillLevelFast(e, replacements, requirePoints, nil, false) - def.Modifier
 		}
 		if level != fxp.Min {
 			baseLevel := level
@@ -889,16 +895,18 @@ func (s *Skill) bestDefaultWithPoints(excluded *SkillDefault) *SkillDefault {
 }
 
 func (s *Skill) bestDefault(excluded *SkillDefault) *SkillDefault {
-	if EntityFromNode(s) == nil || len(s.Defaults) == 0 {
+	e := EntityFromNode(s)
+	if e == nil || len(s.Defaults) == 0 {
 		return nil
 	}
+	requirePoints := !e.SheetSettings.UseSkillTrees
 	excludes := make(map[string]bool)
 	excludes[s.String()] = true
 	var bestDef *SkillDefault
 	best := fxp.Min
 	for _, def := range s.resolveToSpecificDefaults() {
 		// For skill-based defaults, prune out any that already use a default that we are involved with
-		if def.Equivalent(s.Replacements, excluded) || s.inDefaultChain(def, make(map[*Skill]bool)) {
+		if def.Equivalent(s.Replacements, excluded) || (s.inDefaultChain(def, make(map[*Skill]bool)) && requirePoints) {
 			continue
 		}
 		if level := s.calcSkillDefaultLevel(def, excludes); best < level {
@@ -912,11 +920,15 @@ func (s *Skill) bestDefault(excluded *SkillDefault) *SkillDefault {
 
 func (s *Skill) calcSkillDefaultLevel(def *SkillDefault, excludes map[string]bool) fxp.Int {
 	e := EntityFromNode(s)
-	level := def.SkillLevel(e, s.Replacements, true, excludes, !s.IsTechnique())
-	if def.SkillBased() {
+	requirePoints := true
+	if e != nil {
+		requirePoints = !e.SheetSettings.UseSkillTrees
+	}
+	level := def.SkillLevel(e, s.Replacements, requirePoints, excludes, !s.IsTechnique())
+	if def.SkillBased() && e != nil {
 		defName := def.NameWithReplacements(s.Replacements)
 		defSpec := def.SpecializationWithReplacements(s.Replacements)
-		if other := e.BestSkillNamed(defName, defSpec, true, excludes); other != nil {
+		if other := e.BestSkillNamed(defName, defSpec, requirePoints, excludes); other != nil {
 			level -= e.SkillBonusFor(defName, defSpec, s.Tags, nil)
 		}
 	}
@@ -928,8 +940,9 @@ func (s *Skill) inDefaultChain(def *SkillDefault, lookedAt map[*Skill]bool) bool
 	if e == nil || def == nil || !def.SkillBased() {
 		return false
 	}
+	requirePoints := !e.SheetSettings.UseSkillTrees
 	for _, one := range e.SkillNamed(def.NameWithReplacements(s.Replacements),
-		def.SpecializationWithReplacements(s.Replacements), true, nil) {
+		def.SpecializationWithReplacements(s.Replacements), requirePoints, nil) {
 		if one == s {
 			return true
 		}
@@ -950,8 +963,9 @@ func (s *Skill) resolveToSpecificDefaults() []*SkillDefault {
 		if e == nil || def == nil || !def.SkillBased() {
 			result = append(result, def)
 		} else {
+			requirePoints := !e.SheetSettings.UseSkillTrees
 			for _, one := range e.SkillNamed(def.NameWithReplacements(s.Replacements),
-				def.SpecializationWithReplacements(s.Replacements), true,
+				def.SpecializationWithReplacements(s.Replacements), requirePoints,
 				map[string]bool{s.String(): true}) {
 				local := *def
 				local.Name = one.NameWithReplacements()
@@ -969,6 +983,9 @@ func (s *Skill) TechniqueSatisfied(tooltip *xbytes.InsertBuffer, prefix string)
 		return true
 	}
 	e := EntityFromNode(s)
+	if e != nil && e.SheetSettings.UseSkillTrees {
+		return true
+	}
 	sk := e.BestSkillNamed(s.TechniqueDefault.NameWithReplacements(s.Replacements),
 		s.TechniqueDefault.SpecializationWithReplacements(s.Replacements), false, nil)
 	satisfied := sk != nil && (sk.IsTechnique() || sk.Points > 0)
@@ -1123,7 +1140,8 @@ func (s *Skill) SwapDefaults() {
 	def := s.DefaultedFrom
 	s.DefaultedFrom = nil
 	if e := EntityFromNode(s); e != nil {
-		if baseSkill := s.BaseSkill(e, s.bestDefault(nil), true); baseSkill != nil {
+		requirePoints := !e.SheetSettings.UseSkillTrees
+		if baseSkill := s.BaseSkill(e, s.bestDefault(nil), requirePoints); baseSkill != nil {
 			s.DefaultedFrom = s.bestDefaultWithPoints(def)
 			baseSkill.UpdateLevel()
 			s.UpdateLevel()
diff --git a/ux/pageref_name_mappings.go b/ux/pageref_name_mappings.go
index 5b51e71fe..423dfc1e7 100644
--- a/ux/pageref_name_mappings.go
+++ b/ux/pageref_name_mappings.go
@@ -227,6 +227,7 @@ var PageRefKeyNameMappings = map[string]string{
 	"PU7:":    "Power-Ups 7: Wildcard Skills",
 	"PU8:":    "Power-Ups 8: Limitations",
 	"PU9:":    "Power-Ups 9: Alternate Attributes",
+	"PU10:":   "Power-Ups 10: Skill Trees",
 	"PW":      "Powers: The Weird",
 	"PY#:":    "Pyramid 3 issues (replace # with the issue number, but leave out the leading \"3-\")",
 	"PY4-#:":  "Pyramid 4 issues (replace # with the issue number)",
diff --git a/ux/sheet_settings_dockable.go b/ux/sheet_settings_dockable.go
index 2794e545b..0545a2928 100644
--- a/ux/sheet_settings_dockable.go
+++ b/ux/sheet_settings_dockable.go
@@ -53,6 +53,7 @@ type sheetSettingsDockable struct {
 	useHalfStatDefaults                *unison.CheckBox
 	showLiftingSTDamage                *unison.CheckBox
 	showIQBasedDamage                  *unison.CheckBox
+	useSkillTrees                      *unison.CheckBox
 	lengthUnitsPopup                   *unison.PopupMenu[fxp.LengthUnit]
 	weightUnitsPopup                   *unison.PopupMenu[fxp.WeightUnit]
 	userDescDisplayPopup               *unison.PopupMenu[display.Option]
@@ -227,6 +228,11 @@ func (d *sheetSettingsDockable) createOptions(content *unison.Panel) {
 			d.settings().ShowIQBasedDamage = d.showIQBasedDamage.State == check.On
 			d.syncSheet(false)
 		})
+	d.useSkillTrees = d.addCheckBoxWithLink(panel, i18n.Text("Use Skill Trees"), "PU10:4",
+		s.UseSkillTrees, func() {
+			d.settings().UseSkillTrees = d.useSkillTrees.State == check.On
+			d.syncSheet(false)
+		})
 	content.AddChild(panel)
 }
 
@@ -488,6 +494,7 @@ func (d *sheetSettingsDockable) sync() {
 	d.showTitleInsteadOfNameInPageFooter.State = check.FromBool(s.UseTitleInFooter)
 	d.showLiftingSTDamage.State = check.FromBool(s.ShowLiftingSTDamage)
 	d.showIQBasedDamage.State = check.FromBool(s.ShowIQBasedDamage)
+	d.useSkillTrees.State = check.FromBool(s.UseSkillTrees)
 	d.useMultiplicativeModifiers.State = check.FromBool(s.UseMultiplicativeModifiers)
 	d.useHalfStatDefaults.State = check.FromBool(s.UseHalfStatDefaults)
 	d.useModifyDicePlusAdds.State = check.FromBool(s.UseModifyingDicePlusAdds)