Un-overload Object fields and pre-parse damage dice (refactor step 3)

Object.Arm carried four meanings in C (o_arm/o_charges/o_goldval plus ring bonuses); it is now four fields: ArmorClass, Charges, GoldValue, and Bonus. Stats.Arm becomes Stats.ArmorClass. The Charges()/GoldVal() accessor pair is gone. Damage dice strings ("1x4/1x2") are parsed once into DiceSpec — at table definition for the bestiary and weapon tables, at creation for items — instead of re-parsed with atoi on every swing as fight.c roll_em did. ParseDice preserves the C parse semantics exactly, including the junk-tolerant "%%%x0" bestiary placeholder and the "000x0" flytrap reset (regression-tested in dice_test.go); the flytrap's growing grip becomes DiceSpec{{VfHit, 1}}. Save format bumps to 5.4.4-go3 (field renames and retypes would silently zero under gob's match-by-name decoding). No behavior change; full suite green.
2026-07-06 23:07:57 +02:00
parent c75af2ec22
commit 2eff377a73
28 changed files with 268 additions and 186 deletions
--- a/TODO.md
+++ b/TODO.md
@@ -29,14 +29,16 @@ Refactor ground rules:

 # Next Step

-Refactor step 3 (branch refactor/object-fields): un-overload Object
-fields — split Object.Arm into ArmorClass/Charges/GoldValue; parse
-damage dice ("1x4/1x2") once into a DiceSpec type at table definition
-instead of per swing; save-format update with round-trip test
-migration.
+Update the module base path to git.eeqj.de/sneak/rgoue (user request
+2026-07-06): go.mod, all imports in term/ and cmd/, and doc references.

 # Completed Steps

+- 2026-07-06 Refactor step 3 (refactor/object-fields): Object.Arm split
+  into ArmorClass/Charges/GoldValue/Bonus (rings); Stats.Arm →
+  ArmorClass; damage strings parsed once into DiceSpec at table
+  definition (ParseDice keeps C roll_em parse semantics, incl. "%%%x0"
+  and "000x0" edge cases, regression-tested); save format 5.4.4-go3.
 - 2026-07-06 Refactor step 2 (refactor/typed-kinds, b940cfc):
  ObjectKind separates item category from map glyph (Object.Type byte
  → Kind ObjectKind with Glyph()); PotionKind/ScrollKind/RingKind/
--- a/game/command.go
+++ b/game/command.go
@@ -410,7 +410,7 @@ func (g *RogueGame) wizardCommand(ch byte) {
 		g.turnSee(p.On(SenseMonsters))
 	case CTRL('~'):
 		if item := g.getItem("charge", KindWand); item != nil {
-			item.SetCharges(10000)
+			item.Charges = 10000
 		}
 	case CTRL('I'):
 		for range 9 {
@@ -427,7 +427,7 @@ func (g *RogueGame) wizardCommand(ch byte) {
 		obj = newObject()
 		obj.Kind = KindArmor
 		obj.Which = int(ArmorPlateMail)
-		obj.Arm = -5
+		obj.ArmorClass = -5
 		obj.Flags.Set(Known)
 		obj.Count = 1
 		p.CurArmor = obj
--- a/game/dice.go
+++ b/game/dice.go
@@ -0,0 +1,58 @@
+package game
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Rogue expresses damage as strings like "1x4/3x6": one attack rolling
+// 1d4 and a second rolling 3d6. The C code re-parsed these with atoi on
+// every swing (fight.c roll_em); the port parses them once, at table
+// definition or item creation, into a DiceSpec.
+
+// DiceRoll is one attack's dice: Count rolls of a Sides-sided die.
+type DiceRoll struct {
+	Count int
+	Sides int
+}
+
+// DiceSpec is the sequence of attacks a damage string described.
+type DiceSpec []DiceRoll
+
+// ParseDice parses a C damage string with the exact semantics of the
+// roll_em loop: leading digits (C atoi) before and after each 'x', attacks
+// separated by '/'. Junk like the bestiary's "%%%x0" placeholder parses as
+// a single 0x0 attack, as it did in C.
+func ParseDice(s string) DiceSpec {
+	var spec DiceSpec
+	for s != "" {
+		count := cAtoi(s)
+		xi := strings.IndexByte(s, 'x')
+		if xi < 0 {
+			break
+		}
+		s = s[xi+1:]
+		spec = append(spec, DiceRoll{Count: count, Sides: cAtoi(s)})
+		si := strings.IndexByte(s, '/')
+		if si < 0 {
+			break
+		}
+		s = s[si+1:]
+	}
+	return spec
+}
+
+// dice is the table-definition shorthand for ParseDice.
+func dice(s string) DiceSpec { return ParseDice(s) }
+
+// String renders the spec back in the classic "NxM/NxM" form.
+func (d DiceSpec) String() string {
+	var sb strings.Builder
+	for i, r := range d {
+		if i > 0 {
+			sb.WriteByte('/')
+		}
+		fmt.Fprintf(&sb, "%dx%d", r.Count, r.Sides)
+	}
+	return sb.String()
+}
--- a/game/dice_test.go
+++ b/game/dice_test.go
@@ -0,0 +1,45 @@
+package game
+
+import "testing"
+
+// ParseDice must keep the exact semantics of the C roll_em parse loop,
+// including its junk-tolerant edges: the bestiary placeholder "%%%x0" and
+// the flytrap reset "000x0" both mean a single 0x0 attack.
+func TestParseDice(t *testing.T) {
+	cases := []struct {
+		in   string
+		want string
+		len  int
+	}{
+		{"1x4", "1x4", 1},
+		{"1x2/1x5/1x5", "1x2/1x5/1x5", 3},
+		{"2x12/2x4", "2x12/2x4", 2},
+		{"0x0", "0x0", 1},
+		{"000x0", "0x0", 1},
+		{"%%%x0", "0x0", 1},
+		{"", "", 0},
+		{"3", "", 0}, // no 'x': C parses nothing
+	}
+	for _, c := range cases {
+		got := ParseDice(c.in)
+		if len(got) != c.len || got.String() != c.want {
+			t.Errorf("ParseDice(%q) = %v (len %d), want %q (len %d)",
+				c.in, got, len(got), c.want, c.len)
+		}
+	}
+}
+
+// The bestiary and weapon tables must parse to at least one attack each so
+// every creature and weapon actually swings.
+func TestTablesHaveDice(t *testing.T) {
+	for i, m := range monsterTable {
+		if len(m.Stats.Dmg) == 0 {
+			t.Errorf("monster %c (%s) has no attacks", 'A'+i, m.Name)
+		}
+	}
+	for w, iw := range initWeaps {
+		if len(iw.dam) == 0 || len(iw.hrl) == 0 {
+			t.Errorf("weapon %v has empty dice", WeaponKind(w))
+		}
+	}
+}
--- a/game/effects_test.go
+++ b/game/effects_test.go
@@ -72,11 +72,11 @@ func TestReadEnchantArmor(t *testing.T) {
 	ch := give(g, scr)
 	g.scr.term.(*testTerm).input = []byte{ch}

-	before := g.Player.CurArmor.Arm
+	before := g.Player.CurArmor.ArmorClass
 	g.readScroll()
-	if g.Player.CurArmor.Arm != before-1 {
+	if g.Player.CurArmor.ArmorClass != before-1 {
 		t.Errorf("enchant armor: AC %d -> %d, want %d",
-			before, g.Player.CurArmor.Arm, before-1)
+			before, g.Player.CurArmor.ArmorClass, before-1)
 	}
 }

@@ -139,12 +139,12 @@ func TestZapSlowMonster(t *testing.T) {
 	g.scr.term.(*testTerm).input = []byte{ch}
 	g.Delta = Coord{X: 1, Y: 0} // aim at the monster

-	charges := stick.Charges()
+	charges := stick.Charges
 	g.doZap()
 	if !tp.On(Slowed) {
 		t.Error("slow monster wand did not slow")
 	}
-	if stick.Charges() != charges-1 {
+	if stick.Charges != charges-1 {
 		t.Error("zap did not use a charge")
 	}
 }
--- a/game/fight.go
+++ b/game/fight.go
@@ -1,10 +1,6 @@
 package game

-import (
-	"fmt"
-	"strconv"
-	"strings"
-)
+import "strconv"

 // fight.c — all the fighting gets done here.

@@ -245,7 +241,7 @@ func (g *RogueGame) attack(mp *Monster) int {
 				// Venus Flytrap stops the poor guy from moving
 				p.Flags.Set(Held)
 				p.VfHit++
-				g.Monsters['F'-'A'].Stats.Dmg = fmt.Sprintf("%dx1", p.VfHit)
+				g.Monsters['F'-'A'].Stats.Dmg = DiceSpec{{Count: p.VfHit, Sides: 1}}
 				if p.Stats.HP--; p.Stats.HP <= 0 {
 					g.death('F')
 				}
@@ -322,34 +318,34 @@ func (g *RogueGame) rollEm(thatt, thdef *Creature, weap *Object, hurl bool) bool
 	p := &g.Player
 	att := &thatt.Stats
 	def := &thdef.Stats
-	var cp string
+	var attacks DiceSpec
 	var hplus, dplus int
 	if weap == nil {
-		cp = att.Dmg
+		attacks = att.Dmg
 	} else {
 		hplus = weap.HPlus
 		dplus = weap.DPlus
 		if weap == p.CurWeapon {
 			if p.IsRing(Left, RingIncreaseDamage) {
-				dplus += p.CurRing[Left].Arm
+				dplus += p.CurRing[Left].Bonus
 			} else if p.IsRing(Left, RingDexterity) {
-				hplus += p.CurRing[Left].Arm
+				hplus += p.CurRing[Left].Bonus
 			}
 			if p.IsRing(Right, RingIncreaseDamage) {
-				dplus += p.CurRing[Right].Arm
+				dplus += p.CurRing[Right].Bonus
 			} else if p.IsRing(Right, RingDexterity) {
-				hplus += p.CurRing[Right].Arm
+				hplus += p.CurRing[Right].Bonus
 			}
 		}
-		cp = weap.Damage
+		attacks = weap.Damage
 		if hurl {
 			if weap.Flags.Has(Missile) && p.CurWeapon != nil &&
 				WeaponKind(p.CurWeapon.Which) == weap.Launch {
-				cp = weap.HurlDmg
+				attacks = weap.HurlDmg
 				hplus += p.CurWeapon.HPlus
 				dplus += p.CurWeapon.DPlus
 			} else if weap.Launch < 0 {
-				cp = weap.HurlDmg
+				attacks = weap.HurlDmg
 			}
 		}
 	}
@@ -358,40 +354,28 @@ func (g *RogueGame) rollEm(thatt, thdef *Creature, weap *Object, hurl bool) bool
 	if !thdef.Flags.Has(Awake) {
 		hplus += 4
 	}
-	defArm := def.Arm
+	defArm := def.ArmorClass
 	if def == &p.Stats {
 		if p.CurArmor != nil {
-			defArm = p.CurArmor.Arm
+			defArm = p.CurArmor.ArmorClass
 		}
 		if p.IsRing(Left, RingProtection) {
-			defArm -= p.CurRing[Left].Arm
+			defArm -= p.CurRing[Left].Bonus
 		}
 		if p.IsRing(Right, RingProtection) {
-			defArm -= p.CurRing[Right].Arm
+			defArm -= p.CurRing[Right].Bonus
 		}
 	}
 	didHit := false
-	for cp != "" {
-		ndice := cAtoi(cp)
-		xi := strings.IndexByte(cp, 'x')
-		if xi < 0 {
-			break
-		}
-		cp = cp[xi+1:]
-		nsides := cAtoi(cp)
+	for _, atk := range attacks {
 		if g.swing(att.Lvl, defArm, hplus+strPlus[att.Str]) {
-			proll := g.roll(ndice, nsides)
+			proll := g.roll(atk.Count, atk.Sides)
 			damage := dplus + proll + addDam[att.Str]
 			if damage > 0 {
 				def.HP -= damage
 			}
 			didHit = true
 		}
-		si := strings.IndexByte(cp, '/')
-		if si < 0 {
-			break
-		}
-		cp = cp[si+1:]
 	}
 	return didHit
 }
@@ -531,7 +515,7 @@ func (g *RogueGame) killed(tp *Monster, pr bool) {
 	case 'F':
 		p.Flags.Clear(Held)
 		p.VfHit = 0
-		g.Monsters['F'-'A'].Stats.Dmg = "000x0"
+		g.Monsters['F'-'A'].Stats.Dmg = dice("000x0")
 	case 'L':
 		pos, ok := g.fallpos(tp.Pos)
 		if ok {
@@ -540,9 +524,9 @@ func (g *RogueGame) killed(tp *Monster, pr bool) {
 		if ok && g.Depth >= g.MaxDepth {
 			gold := newObject()
 			gold.Kind = KindGold
-			gold.SetGoldVal(g.goldCalc())
+			gold.GoldValue = g.goldCalc()
 			if g.save(VsMagic) {
-				gold.Arm += g.goldCalc() + g.goldCalc() + g.goldCalc() + g.goldCalc()
+				gold.GoldValue += g.goldCalc() + g.goldCalc() + g.goldCalc() + g.goldCalc()
 			}
 			attachObj(&tp.Pack, gold)
 		}
--- a/game/fight_test.go
+++ b/game/fight_test.go
@@ -23,8 +23,8 @@ func spawnAdjacent(g *RogueGame, typ byte) *Monster {

 func TestRollEmParsesMultiAttackDice(t *testing.T) {
 	g := mkGame(t, 42)
-	att := &Creature{Stats: Stats{Str: 16, Lvl: 20, Dmg: "1x4/1x4/1x4"}}
-	def := &Creature{Stats: Stats{Arm: 10, HP: 1000}}
+	att := &Creature{Stats: Stats{Str: 16, Lvl: 20, Dmg: dice("1x4/1x4/1x4")}}
+	def := &Creature{Stats: Stats{ArmorClass: 10, HP: 1000}}
 	def.Flags.Set(Awake)
 	// With attacker level 20 vs armor 10, swing always hits
 	// (rnd(20)+wplus >= (20-20)-10 is always true), so three attacks of
--- a/game/init.go
+++ b/game/init.go
@@ -20,7 +20,7 @@ func (g *RogueGame) initPlayer() {
 	obj = newObject()
 	obj.Kind = KindArmor
 	obj.Which = int(ArmorRingMail)
-	obj.Arm = aClass[ArmorRingMail] - 1
+	obj.ArmorClass = aClass[ArmorRingMail] - 1
 	obj.Flags.Set(Known)
 	obj.Count = 1
 	p.CurArmor = obj
--- a/game/io.go
+++ b/game/io.go
@@ -142,9 +142,9 @@ func (g *RogueGame) status() {
 	p := &g.Player

 	// If nothing has changed since the last status, don't bother.
-	temp := p.Stats.Arm
+	temp := p.Stats.ArmorClass
 	if p.CurArmor != nil {
-		temp = p.CurArmor.Arm
+		temp = p.CurArmor.ArmorClass
 	}
 	if s.init && s.hp == p.Stats.HP && s.exp == p.Stats.Exp &&
 		s.pur == p.Purse && s.arm == temp && s.str == p.Stats.Str &&
--- a/game/misc.go
+++ b/game/misc.go
@@ -279,10 +279,10 @@ func (g *RogueGame) chgStr(amt int) {
 	addStr(&p.Stats.Str, amt)
 	comp := p.Stats.Str
 	if p.IsRing(Left, RingAddStrength) {
-		addStr(&comp, -p.CurRing[Left].Arm)
+		addStr(&comp, -p.CurRing[Left].Bonus)
 	}
 	if p.IsRing(Right, RingAddStrength) {
-		addStr(&comp, -p.CurRing[Right].Arm)
+		addStr(&comp, -p.CurRing[Right].Bonus)
 	}
 	if comp > p.MaxStats.Str {
 		p.MaxStats.Str = comp
--- a/game/monsters.go
+++ b/game/monsters.go
@@ -54,7 +54,7 @@ func (g *RogueGame) newMonster(tp *Monster, typ byte, cp Coord) {
 	tp.Stats.Lvl = mp.Stats.Lvl + levAdd
 	tp.Stats.MaxHP = g.roll(tp.Stats.Lvl, 8)
 	tp.Stats.HP = tp.Stats.MaxHP
-	tp.Stats.Arm = mp.Stats.Arm - levAdd
+	tp.Stats.ArmorClass = mp.Stats.ArmorClass - levAdd
 	tp.Stats.Dmg = mp.Stats.Dmg
 	tp.Stats.Str = mp.Stats.Str
 	tp.Stats.Exp = mp.Stats.Exp + levAdd*10 + expAdd(tp)
@@ -183,10 +183,10 @@ func (g *RogueGame) save(which int) bool {
 	p := &g.Player
 	if which == VsMagic {
 		if p.IsRing(Left, RingProtection) {
-			which -= p.CurRing[Left].Arm
+			which -= p.CurRing[Left].Bonus
 		}
 		if p.IsRing(Right, RingProtection) {
-			which -= p.CurRing[Right].Arm
+			which -= p.CurRing[Right].Bonus
 		}
 	}
 	return g.saveThrow(which, &p.Stats)
--- a/game/move.go
+++ b/game/move.go
@@ -241,7 +241,7 @@ func (g *RogueGame) beTrapped(tc Coord) TrapKind {
 		p.Flags.Clear(Awake)
 		g.msg("a strange white mist envelops you and you fall asleep")
 	case TrapArrow:
-		if g.swing(p.Stats.Lvl-1, p.Stats.Arm, 1) {
+		if g.swing(p.Stats.Lvl-1, p.Stats.ArmorClass, 1) {
 			p.Stats.HP -= g.roll(1, 6)
 			if p.Stats.HP <= 0 {
 				g.msg("an arrow killed you")
@@ -263,7 +263,7 @@ func (g *RogueGame) beTrapped(tc Coord) TrapKind {
 		g.teleport()
 		g.mvaddch(tc.Y, tc.X, Trap)
 	case TrapDart:
-		if !g.swing(p.Stats.Lvl+1, p.Stats.Arm, 1) {
+		if !g.swing(p.Stats.Lvl+1, p.Stats.ArmorClass, 1) {
 			g.msg("a small dart whizzes by your ear and vanishes")
 		} else {
 			p.Stats.HP -= g.roll(1, 4)
@@ -322,7 +322,7 @@ func (g *RogueGame) rndmove(who *Creature) Coord {
 // aren't wearing a magic ring (move.c rust_armor).
 func (g *RogueGame) rustArmor(arm *Object) {
 	if arm == nil || arm.Kind != KindArmor || arm.ArmorKind() == ArmorLeather ||
-		arm.Arm >= 9 {
+		arm.ArmorClass >= 9 {
 		return
 	}

@@ -331,7 +331,7 @@ func (g *RogueGame) rustArmor(arm *Object) {
 			g.msg("the rust vanishes instantly")
 		}
 	} else {
-		arm.Arm++
+		arm.ArmorClass++
 		if !g.Options.Terse {
 			g.msg("your armor appears to be weaker now. Oh my!")
 		} else {
--- a/game/newlevel.go
+++ b/game/newlevel.go
@@ -111,9 +111,9 @@ func (g *RogueGame) putThings() {
 	if g.Depth >= AmuletLevel && !g.HasAmulet {
 		obj := newObject()
 		attachObj(&g.Level.Objects, obj)
-		obj.Damage = "0x0"
-		obj.HurlDmg = "0x0"
-		obj.Arm = 11
+		obj.Damage = dice("0x0")
+		obj.HurlDmg = dice("0x0")
+		obj.ArmorClass = 11
 		obj.Kind = KindAmulet
 		// Put it somewhere
 		obj.Pos, _ = g.findFloor(nil, 0, false)
--- a/game/object.go
+++ b/game/object.go
@@ -94,21 +94,24 @@ func (k ObjectKind) MergesInPack() bool {
 // Object is the _o arm of the C THING union: anything that can lie on the
 // floor or ride in a pack.
 type Object struct {
-	Kind    ObjectKind // what kind of object it is (o_type)
-	Pos     Coord      // where it lives on the screen
-	Text    string     // what it says if you read it
-	Launch  WeaponKind // what you need to launch it (noWeapon if none)
-	PackCh  byte       // what character it is in the pack
-	Damage  string     // damage if used like sword
-	HurlDmg string     // damage if thrown
-	Count   int        // count for plural objects
-	Which   int        // which object of a type it is (index for the Kind's table)
-	HPlus   int        // plusses to hit
-	DPlus   int        // plusses to damage
-	Arm     int        // armor protection — overloaded as in C (see Charges/GoldVal)
-	Flags   ObjFlags
-	Group   int    // group number for this object
-	Label   string // label for object
+	Kind       ObjectKind // what kind of object it is (o_type)
+	Pos        Coord      // where it lives on the screen
+	Text       string     // what it says if you read it
+	Launch     WeaponKind // what you need to launch it (noWeapon if none)
+	PackCh     byte       // what character it is in the pack
+	Damage     DiceSpec   // damage if used like sword
+	HurlDmg    DiceSpec   // damage if thrown
+	Count      int        // count for plural objects
+	Which      int        // which object of a type it is (index for the Kind's table)
+	HPlus      int        // plusses to hit
+	DPlus      int        // plusses to damage
+	ArmorClass int        // armor protection (armor only)
+	Charges    int        // charges remaining (wands and staffs only)
+	GoldValue  int        // worth (gold piles only)
+	Bonus      int        // magic bonus (rings only: protection, add strength, ...)
+	Flags      ObjFlags
+	Group      int    // group number for this object
+	Label      string // label for object
 }

 // newObject is list.c new_item() for objects: a zeroed Object with the
@@ -117,18 +120,6 @@ func newObject() *Object {
 	return &Object{Launch: noWeapon}
 }

-// Charges is the o_charges alias for Arm on wands and staffs.
-func (o *Object) Charges() int { return o.Arm }
-
-// SetCharges stores a charge count in the overloaded Arm field.
-func (o *Object) SetCharges(n int) { o.Arm = n }
-
-// GoldVal is the o_goldval alias for Arm on gold piles.
-func (o *Object) GoldVal() int { return o.Arm }
-
-// SetGoldVal stores a gold value in the overloaded Arm field.
-func (o *Object) SetGoldVal(n int) { o.Arm = n }
-
 // PotionKind returns Which as a potion kind; valid only for KindPotion.
 func (o *Object) PotionKind() PotionKind { return PotionKind(o.Which) }

--- a/game/pack.go
+++ b/game/pack.go
@@ -250,7 +250,7 @@ func (g *RogueGame) pickUp(ch byte) {
 		if obj == nil {
 			return
 		}
-		g.money(obj.GoldVal())
+		g.money(obj.GoldValue)
 		detachObj(&g.Level.Objects, obj)
 		p.Room.GoldVal = 0
 	default:
--- a/game/potions.go
+++ b/game/potions.go
@@ -153,19 +153,19 @@ func (g *RogueGame) quaff() {
 		}
 	case PotionRestoreStrength:
 		if p.IsRing(Left, RingAddStrength) {
-			addStr(&p.Stats.Str, -p.CurRing[Left].Arm)
+			addStr(&p.Stats.Str, -p.CurRing[Left].Bonus)
 		}
 		if p.IsRing(Right, RingAddStrength) {
-			addStr(&p.Stats.Str, -p.CurRing[Right].Arm)
+			addStr(&p.Stats.Str, -p.CurRing[Right].Bonus)
 		}
 		if p.Stats.Str < p.MaxStats.Str {
 			p.Stats.Str = p.MaxStats.Str
 		}
 		if p.IsRing(Left, RingAddStrength) {
-			addStr(&p.Stats.Str, p.CurRing[Left].Arm)
+			addStr(&p.Stats.Str, p.CurRing[Left].Bonus)
 		}
 		if p.IsRing(Right, RingAddStrength) {
-			addStr(&p.Stats.Str, p.CurRing[Right].Arm)
+			addStr(&p.Stats.Str, p.CurRing[Right].Bonus)
 		}
 		g.msg("hey, this tastes great.  It make you feel warm all over")
 	case PotionBlindness:
@@ -212,7 +212,7 @@ func (g *RogueGame) doPot(kind PotionKind, knowit bool) {
 func (o *Object) isMagic() bool {
 	switch o.Kind {
 	case KindArmor:
-		return o.Flags.Has(Protected) || o.Arm != aClass[o.Which]
+		return o.Flags.Has(Protected) || o.ArmorClass != aClass[o.Which]
 	case KindWeapon:
 		return o.HPlus != 0 || o.DPlus != 0
 	case KindPotion, KindScroll, KindWand, KindRing, KindAmulet:
--- a/game/rings.go
+++ b/game/rings.go
@@ -49,7 +49,7 @@ func (g *RogueGame) ringOn() {
 	// Calculate the effect it has on the poor guy.
 	switch obj.RingKind() {
 	case RingAddStrength:
-		g.chgStr(obj.Arm)
+		g.chgStr(obj.Bonus)
 	case RingSeeInvisible:
 		g.invisOn()
 	case RingAggravateMonsters:
@@ -168,7 +168,7 @@ func ringNum(g *RogueGame, obj *Object) string {
 	}
 	switch obj.RingKind() {
 	case RingProtection, RingAddStrength, RingIncreaseDamage, RingDexterity:
-		return fmt.Sprintf(" [%s]", num(obj.Arm, 0, Ring))
+		return fmt.Sprintf(" [%s]", num(obj.Bonus, 0, Ring))
 	}
 	return ""
 }
--- a/game/rip.go
+++ b/game/rip.go
@@ -124,8 +124,8 @@ func (g *RogueGame) totalWinner() {
 			obj.Flags.Set(Known)
 		case KindArmor:
 			worth = it.Armors[obj.Which].Worth
-			worth += (9 - obj.Arm) * 100
-			worth += 10 * (aClass[obj.Which] - obj.Arm)
+			worth += (9 - obj.ArmorClass) * 100
+			worth += 10 * (aClass[obj.Which] - obj.ArmorClass)
 			obj.Flags.Set(Known)
 		case KindScroll:
 			op := &it.Scrolls[obj.Which]
@@ -146,8 +146,8 @@ func (g *RogueGame) totalWinner() {
 			worth = op.Worth
 			if obj.RingKind() == RingAddStrength || obj.RingKind() == RingIncreaseDamage ||
 				obj.RingKind() == RingProtection || obj.RingKind() == RingDexterity {
-				if obj.Arm > 0 {
-					worth += obj.Arm * 100
+				if obj.Bonus > 0 {
+					worth += obj.Bonus * 100
 				} else {
 					worth = 10
 				}
@@ -160,7 +160,7 @@ func (g *RogueGame) totalWinner() {
 		case KindWand:
 			op := &it.Sticks[obj.Which]
 			worth = op.Worth
-			worth += 20 * obj.Charges()
+			worth += 20 * obj.Charges
 			if !obj.Flags.Has(Known) {
 				worth /= 2
 			}
--- a/game/rooms.go
+++ b/game/rooms.go
@@ -88,7 +88,7 @@ func (g *RogueGame) doRooms() {
 		if g.rnd(2) == 0 && (!g.HasAmulet || g.Depth >= g.MaxDepth) {
 			gold := newObject()
 			rp.GoldVal = g.goldCalc()
-			gold.SetGoldVal(rp.GoldVal)
+			gold.GoldValue = rp.GoldVal
 			rp.Gold, _ = g.findFloorIn(rp, 0, false)
 			gold.Pos = rp.Gold
 			g.Level.SetChar(rp.Gold.Y, rp.Gold.X, Gold)
--- a/game/save.go
+++ b/game/save.go
@@ -13,8 +13,10 @@ import (

 // saveFormatVersion identifies the snapshot layout; it changes whenever a
 // field rename or retype would make gob silently mis-decode an older
-// save ("go2": Object.Type became Kind ObjectKind).
-const saveFormatVersion = Release + "-go2"
+// save ("go2": Object.Type became Kind ObjectKind; "go3": Object.Arm split
+// into ArmorClass/Charges/GoldValue/Bonus, damage strings became
+// DiceSpec).
+const saveFormatVersion = Release + "-go3"

 // destRef encodes a monster's chase target (state.c rs_write_thing's
 // (kind, index) pairs).
--- a/game/save_test.go
+++ b/game/save_test.go
@@ -15,7 +15,7 @@ func TestSaveRestoreRoundTrip(t *testing.T) {
 	g.HasAmulet = true
 	g.Items.Potions[PotionHealing].Know = true
 	g.Items.Scrolls[ScrollMagicMapping].Guess = "map???"
-	g.Monsters['F'-'A'].Stats.Dmg = "3x1" // mutated bestiary must survive
+	g.Monsters['F'-'A'].Stats.Dmg = dice("3x1") // mutated bestiary must survive
 	if len(g.Level.Monsters) > 0 {
 		g.Level.Monsters[0].Flags.Set(Awake)
 		g.Level.Monsters[0].Dest = &g.Player.Pos
@@ -48,7 +48,7 @@ func TestSaveRestoreRoundTrip(t *testing.T) {
 	if h.Items.Scrolls[ScrollMagicMapping].Guess != "map???" {
 		t.Error("scroll guess lost")
 	}
-	if h.Monsters['F'-'A'].Stats.Dmg != "3x1" {
+	if h.Monsters['F'-'A'].Stats.Dmg.String() != "3x1" {
 		t.Error("mutated bestiary lost")
 	}
 	if h.Rng.Seed != g.Rng.Seed {
--- a/game/scrolls.go
+++ b/game/scrolls.go
@@ -42,7 +42,7 @@ func (g *RogueGame) readScroll() {
 		g.msg("your hands begin to glow %s", g.pickColor("red"))
 	case ScrollEnchantArmor:
 		if p.CurArmor != nil {
-			p.CurArmor.Arm--
+			p.CurArmor.ArmorClass--
 			p.CurArmor.Flags.Clear(Cursed)
 			g.msg("your armor glows %s for a moment", g.pickColor("silver"))
 		}
--- a/game/sticks.go
+++ b/game/sticks.go
@@ -16,7 +16,7 @@ func (g *RogueGame) doZap() {
 		g.msg("you can't zap with that!")
 		return
 	}
-	if obj.Charges() == 0 {
+	if obj.Charges == 0 {
 		g.msg("nothing happens")
 		return
 	}
@@ -111,7 +111,7 @@ func (g *RogueGame) doZap() {
 		g.Items.Sticks[WandMagicMissile].Know = true
 		bolt := newObject()
 		bolt.Kind = KindGold // C set o_type='*': draws a '*' and is not a weapon
-		bolt.HurlDmg = "1x4"
+		bolt.HurlDmg = dice("1x4")
 		bolt.HPlus = 100
 		bolt.DPlus = 1
 		bolt.Flags = Missile
@@ -167,7 +167,7 @@ func (g *RogueGame) doZap() {
 		g.Items.Sticks[obj.Which].Know = true
 	case WandNothing:
 	}
-	obj.SetCharges(obj.Charges() - 1)
+	obj.Charges--
 }

 // drain does the drain-hit-points-from-player schtick (sticks.c drain).
@@ -213,7 +213,7 @@ func (g *RogueGame) fireBolt(start Coord, dir *Coord, name string) {
 	bolt := newObject()
 	bolt.Kind = KindWeapon
 	bolt.Which = int(WeaponFlame)
-	bolt.HurlDmg = "6x6"
+	bolt.HurlDmg = dice("6x6")
 	bolt.HPlus = 100
 	bolt.DPlus = 0
 	g.Items.Weapons[WeaponFlame].Name = name
@@ -322,17 +322,17 @@ func (g *RogueGame) fireBolt(start Coord, dir *Coord, name string) {
 // fixStick sets up a new wand or staff (sticks.c fix_stick).
 func (g *RogueGame) fixStick(cur *Object) {
 	if g.Items.WandType[cur.Which] == "staff" {
-		cur.Damage = "2x3"
+		cur.Damage = dice("2x3")
 	} else {
-		cur.Damage = "1x1"
+		cur.Damage = dice("1x1")
 	}
-	cur.HurlDmg = "1x1"
+	cur.HurlDmg = dice("1x1")

 	switch cur.WandKind() {
 	case WandLight:
-		cur.SetCharges(g.rnd(10) + 10)
+		cur.Charges = g.rnd(10) + 10
 	default:
-		cur.SetCharges(g.rnd(5) + 3)
+		cur.Charges = g.rnd(5) + 3
 	}
 }

@@ -343,7 +343,7 @@ func chargeStr(g *RogueGame, obj *Object) string {
 		return ""
 	}
 	if g.Options.Terse {
-		return fmt.Sprintf(" [%d]", obj.Charges())
+		return fmt.Sprintf(" [%d]", obj.Charges)
 	}
-	return fmt.Sprintf(" [%d charges]", obj.Charges())
+	return fmt.Sprintf(" [%d charges]", obj.Charges)
 }
--- a/game/tables.go
+++ b/game/tables.go
@@ -6,7 +6,7 @@ package game
 // change during play) are cloned into RogueGame.Items by NewGame.

 // initStats is the C INIT_STATS: the player's starting statistics.
-var initStats = Stats{Str: 16, Exp: 0, Lvl: 1, Arm: 10, HP: 12, Dmg: "1x4", MaxHP: 12}
+var initStats = Stats{Str: 16, Exp: 0, Lvl: 1, ArmorClass: 10, HP: 12, Dmg: dice("1x4"), MaxHP: 12}

 // aClass is extern.c a_class[]: armor class for each armor type.
 var aClass = [NumArmorTypes]int{
@@ -47,32 +47,32 @@ var invTName = []string{"Overwrite", "Slow", "Clear"}
 // rolled from the level at creation time.
 var monsterTable = [26]MonsterKind{
 	/* Name             CARRY  FLAGS                          str exp  lvl arm hp  dmg */
-	{"aquator", 0, Mean, Stats{10, 20, 5, 2, 1, "0x0/0x0", 0}},
-	{"bat", 0, Flying, Stats{10, 1, 1, 3, 1, "1x2", 0}},
-	{"centaur", 15, 0, Stats{10, 17, 4, 4, 1, "1x2/1x5/1x5", 0}},
-	{"dragon", 100, Mean, Stats{10, 5000, 10, -1, 1, "1x8/1x8/3x10", 0}},
-	{"emu", 0, Mean, Stats{10, 2, 1, 7, 1, "1x2", 0}},
-	{"venus flytrap", 0, Mean, Stats{10, 80, 8, 3, 1, "%%%x0", 0}},
-	{"griffin", 20, Mean | Flying | Regenerates, Stats{10, 2000, 13, 2, 1, "4x3/3x5", 0}},
-	{"hobgoblin", 0, Mean, Stats{10, 3, 1, 5, 1, "1x8", 0}},
-	{"ice monster", 0, 0, Stats{10, 5, 1, 9, 1, "0x0", 0}},
-	{"jabberwock", 70, 0, Stats{10, 3000, 15, 6, 1, "2x12/2x4", 0}},
-	{"kestrel", 0, Mean | Flying, Stats{10, 1, 1, 7, 1, "1x4", 0}},
-	{"leprechaun", 0, 0, Stats{10, 10, 3, 8, 1, "1x1", 0}},
-	{"medusa", 40, Mean, Stats{10, 200, 8, 2, 1, "3x4/3x4/2x5", 0}},
-	{"nymph", 100, 0, Stats{10, 37, 3, 9, 1, "0x0", 0}},
-	{"orc", 15, Greedy, Stats{10, 5, 1, 6, 1, "1x8", 0}},
-	{"phantom", 0, Invisible, Stats{10, 120, 8, 3, 1, "4x4", 0}},
-	{"quagga", 0, Mean, Stats{10, 15, 3, 3, 1, "1x5/1x5", 0}},
-	{"rattlesnake", 0, Mean, Stats{10, 9, 2, 3, 1, "1x6", 0}},
-	{"snake", 0, Mean, Stats{10, 2, 1, 5, 1, "1x3", 0}},
-	{"troll", 50, Regenerates | Mean, Stats{10, 120, 6, 4, 1, "1x8/1x8/2x6", 0}},
-	{"black unicorn", 0, Mean, Stats{10, 190, 7, -2, 1, "1x9/1x9/2x9", 0}},
-	{"vampire", 20, Regenerates | Mean, Stats{10, 350, 8, 1, 1, "1x10", 0}},
-	{"wraith", 0, 0, Stats{10, 55, 5, 4, 1, "1x6", 0}},
-	{"xeroc", 30, 0, Stats{10, 100, 7, 7, 1, "4x4", 0}},
-	{"yeti", 30, 0, Stats{10, 50, 4, 6, 1, "1x6/1x6", 0}},
-	{"zombie", 0, Mean, Stats{10, 6, 2, 8, 1, "1x8", 0}},
+	{"aquator", 0, Mean, Stats{10, 20, 5, 2, 1, dice("0x0/0x0"), 0}},
+	{"bat", 0, Flying, Stats{10, 1, 1, 3, 1, dice("1x2"), 0}},
+	{"centaur", 15, 0, Stats{10, 17, 4, 4, 1, dice("1x2/1x5/1x5"), 0}},
+	{"dragon", 100, Mean, Stats{10, 5000, 10, -1, 1, dice("1x8/1x8/3x10"), 0}},
+	{"emu", 0, Mean, Stats{10, 2, 1, 7, 1, dice("1x2"), 0}},
+	{"venus flytrap", 0, Mean, Stats{10, 80, 8, 3, 1, dice("%%%x0"), 0}},
+	{"griffin", 20, Mean | Flying | Regenerates, Stats{10, 2000, 13, 2, 1, dice("4x3/3x5"), 0}},
+	{"hobgoblin", 0, Mean, Stats{10, 3, 1, 5, 1, dice("1x8"), 0}},
+	{"ice monster", 0, 0, Stats{10, 5, 1, 9, 1, dice("0x0"), 0}},
+	{"jabberwock", 70, 0, Stats{10, 3000, 15, 6, 1, dice("2x12/2x4"), 0}},
+	{"kestrel", 0, Mean | Flying, Stats{10, 1, 1, 7, 1, dice("1x4"), 0}},
+	{"leprechaun", 0, 0, Stats{10, 10, 3, 8, 1, dice("1x1"), 0}},
+	{"medusa", 40, Mean, Stats{10, 200, 8, 2, 1, dice("3x4/3x4/2x5"), 0}},
+	{"nymph", 100, 0, Stats{10, 37, 3, 9, 1, dice("0x0"), 0}},
+	{"orc", 15, Greedy, Stats{10, 5, 1, 6, 1, dice("1x8"), 0}},
+	{"phantom", 0, Invisible, Stats{10, 120, 8, 3, 1, dice("4x4"), 0}},
+	{"quagga", 0, Mean, Stats{10, 15, 3, 3, 1, dice("1x5/1x5"), 0}},
+	{"rattlesnake", 0, Mean, Stats{10, 9, 2, 3, 1, dice("1x6"), 0}},
+	{"snake", 0, Mean, Stats{10, 2, 1, 5, 1, dice("1x3"), 0}},
+	{"troll", 50, Regenerates | Mean, Stats{10, 120, 6, 4, 1, dice("1x8/1x8/2x6"), 0}},
+	{"black unicorn", 0, Mean, Stats{10, 190, 7, -2, 1, dice("1x9/1x9/2x9"), 0}},
+	{"vampire", 20, Regenerates | Mean, Stats{10, 350, 8, 1, 1, dice("1x10"), 0}},
+	{"wraith", 0, 0, Stats{10, 55, 5, 4, 1, dice("1x6"), 0}},
+	{"xeroc", 30, 0, Stats{10, 100, 7, 7, 1, dice("4x4"), 0}},
+	{"yeti", 30, 0, Stats{10, 50, 4, 6, 1, dice("1x6/1x6"), 0}},
+	{"zombie", 0, Mean, Stats{10, 6, 2, 8, 1, dice("1x8"), 0}},
 }

 // Base ObjInfo tables (extern.c). These are templates: NewGame copies them
--- a/game/things.go
+++ b/game/things.go
@@ -69,11 +69,11 @@ func (g *RogueGame) invName(obj *Object, drop bool) string {
 	case KindArmor:
 		sp := it.Armors[which].Name
 		if obj.Flags.Has(Known) {
-			fmt.Fprintf(&pb, "%s %s [", num(aClass[which]-obj.Arm, 0, Armor), sp)
+			fmt.Fprintf(&pb, "%s %s [", num(aClass[which]-obj.ArmorClass, 0, Armor), sp)
 			if !g.Options.Terse {
 				pb.WriteString("protection ")
 			}
-			fmt.Fprintf(&pb, "%d]", 10-obj.Arm)
+			fmt.Fprintf(&pb, "%d]", 10-obj.ArmorClass)
 		} else {
 			pb.WriteString(sp)
 		}
@@ -83,7 +83,7 @@ func (g *RogueGame) invName(obj *Object, drop bool) string {
 	case KindAmulet:
 		pb.WriteString("The Amulet of Yendor")
 	case KindGold:
-		fmt.Fprintf(&pb, "%d Gold pieces", obj.GoldVal())
+		fmt.Fprintf(&pb, "%d Gold pieces", obj.GoldValue)
 	}

 	out := pb.String()
@@ -168,7 +168,7 @@ func (g *RogueGame) dropCheck(obj *Object) bool {
 		p.CurRing[hand] = nil
 		switch obj.RingKind() {
 		case RingAddStrength:
-			g.chgStr(-obj.Arm)
+			g.chgStr(-obj.Bonus)
 		case RingSeeInvisible:
 			g.unsee(0)
 			g.Extinguish(DUnsee)
@@ -180,9 +180,9 @@ func (g *RogueGame) dropCheck(obj *Object) bool {
 // newThing returns a new random thing for the dungeon (things.c new_thing).
 func (g *RogueGame) newThing() *Object {
 	cur := newObject()
-	cur.Damage = "0x0"
-	cur.HurlDmg = "0x0"
-	cur.Arm = 11
+	cur.Damage = dice("0x0")
+	cur.HurlDmg = dice("0x0")
+	cur.ArmorClass = 11
 	cur.Count = 1

 	// Decide what kind of object it will be; if we haven't had food for a
@@ -219,20 +219,20 @@ func (g *RogueGame) newThing() *Object {
 	case 4:
 		cur.Kind = KindArmor
 		cur.Which = pickOne(g, g.Items.Armors[:])
-		cur.Arm = aClass[cur.Which]
+		cur.ArmorClass = aClass[cur.Which]
 		if r := g.rnd(100); r < 20 {
 			cur.Flags.Set(Cursed)
-			cur.Arm += g.rnd(3) + 1
+			cur.ArmorClass += g.rnd(3) + 1
 		} else if r < 28 {
-			cur.Arm -= g.rnd(3) + 1
+			cur.ArmorClass -= g.rnd(3) + 1
 		}
 	case 5:
 		cur.Kind = KindRing
 		cur.Which = pickOne(g, g.Items.Rings[:])
 		switch cur.RingKind() {
 		case RingAddStrength, RingProtection, RingDexterity, RingIncreaseDamage:
-			if cur.Arm = g.rnd(3); cur.Arm == 0 {
-				cur.Arm = -1
+			if cur.Bonus = g.rnd(3); cur.Bonus == 0 {
+				cur.Bonus = -1
 				cur.Flags.Set(Cursed)
 			}
 		case RingAggravateMonsters, RingTeleportation:
--- a/game/types.go
+++ b/game/types.go
@@ -374,13 +374,13 @@ type Coord struct {

 // Stats describes a fighting being (rogue.h struct stats).
 type Stats struct {
-	Str   int    // strength (s_str; 3..31)
-	Exp   int    // experience
-	Lvl   int    // level of mastery
-	Arm   int    // armor class
-	HP    int    // hit points (s_hpt)
-	Dmg   string // damage dice, e.g. "1x4/1x2"
-	MaxHP int
+	Str        int      // strength (s_str; 3..31)
+	Exp        int      // experience
+	Lvl        int      // level of mastery
+	ArmorClass int      // armor class (s_arm)
+	HP         int      // hit points (s_hpt)
+	Dmg        DiceSpec // damage dice, e.g. "1x4/1x2"
+	MaxHP      int
 }

 // Room describes a room or passage network (rogue.h struct room).
--- a/game/weapons.go
+++ b/game/weapons.go
@@ -123,20 +123,20 @@ func (g *RogueGame) wield() {

 // initWeaps is the weapons.c init_dam[] table.
 var initWeaps = [NumWeaponTypes]struct {
-	dam    string     // damage when wielded
-	hrl    string     // damage when thrown
+	dam    DiceSpec   // damage when wielded
+	hrl    DiceSpec   // damage when thrown
 	launch WeaponKind // launching weapon
 	flags  ObjFlags
 }{
-	{"2x4", "1x3", noWeapon, 0},                    // WeaponMace
-	{"3x4", "1x2", noWeapon, 0},                    // Long sword
-	{"1x1", "1x1", noWeapon, 0},                    // WeaponBow
-	{"1x1", "2x3", WeaponBow, Stackable | Missile}, // WeaponArrow
-	{"1x6", "1x4", noWeapon, Missile},              // WeaponDagger
-	{"4x4", "1x2", noWeapon, 0},                    // 2h sword
-	{"1x1", "1x3", noWeapon, Stackable | Missile},  // WeaponDart
-	{"1x2", "2x4", noWeapon, Stackable | Missile},  // Shuriken
-	{"2x3", "1x6", noWeapon, Missile},              // WeaponSpear
+	{dice("2x4"), dice("1x3"), noWeapon, 0},                    // WeaponMace
+	{dice("3x4"), dice("1x2"), noWeapon, 0},                    // Long sword
+	{dice("1x1"), dice("1x1"), noWeapon, 0},                    // WeaponBow
+	{dice("1x1"), dice("2x3"), WeaponBow, Stackable | Missile}, // WeaponArrow
+	{dice("1x6"), dice("1x4"), noWeapon, Missile},              // WeaponDagger
+	{dice("4x4"), dice("1x2"), noWeapon, 0},                    // 2h sword
+	{dice("1x1"), dice("1x3"), noWeapon, Stackable | Missile},  // WeaponDart
+	{dice("1x2"), dice("2x4"), noWeapon, Stackable | Missile},  // Shuriken
+	{dice("2x3"), dice("1x6"), noWeapon, Missile},              // WeaponSpear
 }

 // initWeapon sets up a new weapon (weapons.c init_weapon).
--- a/game/wizard.go
+++ b/game/wizard.go
@@ -38,12 +38,12 @@ func (g *RogueGame) createObj() {
 				obj.HPlus += g.rnd(3) + 1
 			}
 		} else {
-			obj.Arm = aClass[obj.Which]
+			obj.ArmorClass = aClass[obj.Which]
 			if bless == '-' {
-				obj.Arm += g.rnd(3) + 1
+				obj.ArmorClass += g.rnd(3) + 1
 			}
 			if bless == '+' {
-				obj.Arm -= g.rnd(3) + 1
+				obj.ArmorClass -= g.rnd(3) + 1
 			}
 		}
 	case obj.Kind == KindRing:
@@ -54,9 +54,9 @@ func (g *RogueGame) createObj() {
 			g.Msgs.Mpos = 0
 			if bless == '-' {
 				obj.Flags.Set(Cursed)
-				obj.Arm = -1
+				obj.Bonus = -1
 			} else {
-				obj.Arm = g.rnd(2) + 1
+				obj.Bonus = g.rnd(2) + 1
 			}
 		case RingAggravateMonsters, RingTeleportation:
 			obj.Flags.Set(Cursed)
@@ -67,7 +67,7 @@ func (g *RogueGame) createObj() {
 		g.msg("how much?")
 		buf := ""
 		if g.getStr(&buf, g.scr.Std) == Norm {
-			obj.SetGoldVal(cAtoi(buf))
+			obj.GoldValue = cAtoi(buf)
 		}
 	}
 	g.addPack(obj, false)
@@ -169,7 +169,7 @@ func (g *RogueGame) teleport() {
 	if p.On(Held) {
 		p.Flags.Clear(Held)
 		p.VfHit = 0
-		g.Monsters['F'-'A'].Stats.Dmg = "000x0"
+		g.Monsters['F'-'A'].Stats.Dmg = dice("000x0")
 	}
 	g.NoMove = 0
 	g.Count = 0