diff --git a/internal/controller/controller.go b/internal/controller/controller.go
index 95cdb13..5a31de1 100644
--- a/internal/controller/controller.go
+++ b/internal/controller/controller.go
@@ -20,10 +20,14 @@ type Repo interface {
 	// SaveState stores current game state updated between turns
 	SaveState(*game.Game) error
 
-	// LoadState retrieves game current state
+	// LoadState retrieves game current state with required lock acquisition
 	LoadState() (*game.Game, error)
 
+	// LoadStateSafe retrieves game current state without preliminary locking
 	LoadStateSafe() (*game.Game, error)
+
+	// SaveBattle stores
+	SaveBattle(t uint, b *game.BattleReport) error
 }
 
 type Controller struct {
diff --git a/internal/game/turn/turn.go b/internal/game/turn/turn.go
index 31c2dfd..36aaddf 100644
--- a/internal/game/turn/turn.go
+++ b/internal/game/turn/turn.go
@@ -1,13 +1,76 @@
 package turn
 
-import "github.com/iliadenisov/galaxy/internal/model/game"
+import (
+	"fmt"
+
+	"github.com/iliadenisov/galaxy/internal/controller"
+	e "github.com/iliadenisov/galaxy/internal/error"
+	"github.com/iliadenisov/galaxy/internal/model/game"
+)
+
+func MakeTurn(r controller.Repo, g *game.Game) error {
+	// Next turn
+	g.Age += 1
 
-func MakeTurn(g *game.Game) error {
 	// 01. Корабли, где это возможно, объединяются в группы.
 	game.JoinEqualGroups(g)
 
 	// 02. Враждующие корабли вступают в схватку.
-	game.ProduceBattles(g)
+	battles := game.ProduceBattles(g)
 
+	// Internal control: after battles there are can't be groups with no ships left
+	for i := range g.ShipGroups {
+		if g.ShipGroups[i].Number == 0 {
+			return e.NewGameStateError("")
+		}
+	}
+
+	// Last step: storing battles
+	if len(battles) > 0 {
+		for i := range battles {
+			br := TransformBattle(g, battles[i])
+			if err := r.SaveBattle(g.Age, br); err != nil {
+				return err
+			}
+		}
+	}
 	return nil
 }
+
+func TransformBattle(g *game.Game, b *game.Battle) *game.BattleReport {
+	p, ok := game.PlanetByNum(g, b.Planet)
+	if !ok {
+		panic(fmt.Sprintf("TransformBattle: no planet with number #%d", b.Planet))
+	}
+	r := &game.BattleReport{
+		ID:         b.ID,
+		Planet:     b.Planet,
+		PlanetName: p.Name,
+		Races:      make(map[int]string),
+		Ships:      make(map[int]string),
+		Protocol:   make([]game.BattleActionReport, len(b.Protocol)),
+	}
+
+	cacheShipClass := make(map[string]int)
+
+	shipClass := func(shipClass string) int {
+		if v, ok := cacheShipClass[shipClass]; ok {
+			return v
+		} else {
+			l := len(r.Ships)
+			r.Ships[l] = shipClass
+			cacheShipClass[shipClass] = l
+			return l
+		}
+	}
+
+	for i := range b.Protocol {
+		r.Protocol[i] = game.BattleActionReport{
+			AttackerShipClass: shipClass(b.ShipClassName(b.Protocol[i].Attacker)),
+			DefenderShipClass: shipClass(b.ShipClassName(b.Protocol[i].Defenter)),
+			Destroyed:         b.Protocol[i].Destroyed,
+		}
+	}
+
+	return r
+}
diff --git a/internal/model/game/battle.go b/internal/model/game/battle.go
index 2de2b7b..fcb9ff4 100644
--- a/internal/model/game/battle.go
+++ b/internal/model/game/battle.go
@@ -1,6 +1,7 @@
 package game
 
 import (
+	"encoding/json"
 	"fmt"
 	"maps"
 	"math"
@@ -11,29 +12,67 @@ import (
 )
 
 type Battle struct {
-	Planet       uint
-	BattleReport BattleReport
+	ID     uuid.UUID
+	Planet uint
+	// True = In_Battle, False = Out_Battle
+	observerGroups map[int]bool
+	Protocol       []BattleAction
 
 	shipAmmo map[int]uint
+	shipName map[int]string
 	attacker map[int]map[int]float64 // a group able to attack and destroy an opponent with some probability > 0
 }
 
-type BattleReport struct {
-	BattleAction []BattleAction
-}
-
 type BattleAction struct {
 	Attacker  int
 	Defenter  int
 	Destroyed bool
 }
 
-func CollectPlanetGroups(g *Game, cacheShipGroupRaceID map[int]int, cacheShipClass map[int]*ShipType) map[uint][]int {
-	planetGroup := make(map[uint][]int)
+func (b Battle) ShipClassName(groupIndex int) string {
+	if v, ok := b.shipName[groupIndex]; ok {
+		return v
+	} else {
+		panic(fmt.Sprintf("Battle.ShipClassName: no name stored for groupIndex=%d", groupIndex))
+	}
+}
+
+type BattleReport struct {
+	ID         uuid.UUID            `json:"id"`
+	Planet     uint                 `json:"planet"`
+	PlanetName string               `json:"planet_name"`
+	Races      map[int]string       `json:"races"`
+	Ships      map[int]string       `json:"ships"`
+	Protocol   []BattleActionReport `json:"protocol"`
+}
+
+type BattleActionReport struct {
+	Attacker          int  `json:"r1"`
+	AttackerShipClass int  `json:"s1"`
+	Defender          int  `json:"r2"`
+	DefenderShipClass int  `json:"s2"`
+	Destroyed         bool `json:"d"`
+}
+
+type ShipClassBattle struct {
+	ClassName string     `json:"class"`
+	Tech      TechSet    `json:"tech"`
+	Number    uint       `json:"number"`
+	CargoType *CargoType `json:"loadType,omitempty"`
+	Quantity  float64    `json:"quantity"`
+	Left      uint       `json:"left"`
+}
+
+func CollectPlanetGroups(g *Game, cacheShipGroupRaceID map[int]int, cacheShipClass map[int]*ShipType) map[uint]map[int]bool {
+	planetGroup := make(map[uint]map[int]bool)
 	for groupIndex := range g.ShipGroups {
-		if g.ShipGroups[groupIndex].State() == StateInOrbit {
+		state := g.ShipGroups[groupIndex].State()
+		if state == StateInOrbit || state == StateUpgrade {
 			planetNumber := g.ShipGroups[groupIndex].Destination
-			planetGroup[planetNumber] = append(planetGroup[planetNumber], groupIndex)
+			if _, ok := planetGroup[planetNumber]; !ok {
+				planetGroup[planetNumber] = make(map[int]bool)
+			}
+			planetGroup[planetNumber][groupIndex] = false
 
 			if _, ok := cacheShipGroupRaceID[groupIndex]; !ok {
 				cacheShipGroupRaceID[groupIndex] = RaceIndex(g, g.ShipGroups[groupIndex].OwnerID)
@@ -57,6 +96,10 @@ func CollectPlanetGroups(g *Game, cacheShipGroupRaceID map[int]int, cacheShipCla
 	return planetGroup
 }
 
+func FilterBattleGroups(g *Game, groups map[int]bool) []int {
+	return slices.DeleteFunc(slices.Collect(maps.Keys(groups)), func(groupIndex int) bool { return g.ShipGroups[groupIndex].State() != StateInOrbit })
+}
+
 func CacheRelations(g *Game, cacheShipGroupRaceID map[int]int) map[int]map[int]Relation {
 	cache := make(map[int]map[int]Relation)
 	ri := make(map[int]bool)
@@ -132,8 +175,8 @@ func ProduceBattles(g *Game) []*Battle {
 		clear(cacheProbability)
 	}()
 
-	planetGroup := CollectPlanetGroups(g, cacheShipGroupRaceID, cacheShipClass)
-	if len(planetGroup) == 0 {
+	planetGroups := CollectPlanetGroups(g, cacheShipGroupRaceID, cacheShipClass)
+	if len(planetGroups) == 0 {
 		return nil
 	}
 
@@ -144,35 +187,42 @@ func ProduceBattles(g *Game) []*Battle {
 
 	result := make([]*Battle, 0)
 
-	for pl, groups := range planetGroup {
+	for pl, observerGroups := range planetGroups {
+		battleGroups := FilterBattleGroups(g, observerGroups)
 		b := &Battle{
-			Planet:   pl,
-			attacker: make(map[int]map[int]float64),
-			shipAmmo: make(map[int]uint),
+			Planet:         pl,
+			observerGroups: observerGroups,
+			attacker:       make(map[int]map[int]float64),
+			shipAmmo:       make(map[int]uint),
+			shipName:       make(map[int]string),
 		}
 
-		for i := range groups {
-			attIdx := groups[i]
+		for i := range battleGroups {
+			attIdx := battleGroups[i]
 
 			// Ships with no Ammo will never attack somebody
 			if cacheShipClass[attIdx].Armament == 0 {
 				continue
 			}
 
-			// TODO: remove slices.Clone?
-			opponents := slices.DeleteFunc(slices.Clone(groups), func(defIdx int) bool {
+			opponents := slices.DeleteFunc(slices.Clone(battleGroups), func(defIdx int) bool {
 				return FilterBattleOpponents(g, attIdx, defIdx, cacheShipGroupRaceID, cacheRelation, cacheShipClass, cacheProbability)
 			})
 			if len(opponents) > 0 {
 				b.shipAmmo[attIdx] = cacheShipClass[attIdx].Armament
+				b.shipName[attIdx] = cacheShipClass[attIdx].Name
+				b.observerGroups[attIdx] = true
 				for _, defIdx := range opponents {
 					b.attacker[attIdx][defIdx] = cacheProbability[attIdx][defIdx]
+					b.shipName[defIdx] = cacheShipClass[defIdx].Name
+					b.observerGroups[defIdx] = true
 				}
 			}
 		}
 
 		if len(b.attacker) > 0 {
 			SingleBattle(g, b)
+			b.ID = uuid.New()
 			result = append(result, b)
 		}
 
@@ -203,7 +253,7 @@ func SingleBattle(g *Game, b *Battle) {
 				panic("SingleBattle: probability unexpected: value <= 0")
 			}
 
-			b.BattleReport.BattleAction = append(b.BattleReport.BattleAction, BattleAction{
+			b.Protocol = append(b.Protocol, BattleAction{
 				Attacker:  attIdx,
 				Defenter:  defIdx,
 				Destroyed: destroyed,
@@ -220,6 +270,8 @@ func SingleBattle(g *Game, b *Battle) {
 						delete(b.attacker, attIdx) // Remove attacker if he lost all opponents
 					}
 				}
+				// FIXME: удалять ShipGroups после генерирования пользовательского отчёта
+				// g.ShipGroups = append(g.ShipGroups[:defIdx], g.ShipGroups[defIdx+1:]...)
 			}
 			if len(b.attacker) == 0 {
 				break
@@ -245,3 +297,11 @@ func DestructionProbability(attWeapons, attWeaponsTech, defShields, defShiledsTe
 func EffectiveDefence(defShields, defShiledsTech, defFullMass float64) float64 {
 	return defShields * defShiledsTech / math.Pow(defFullMass, 1./3.) * math.Pow(30., 1./3.)
 }
+
+func (b BattleReport) MarshalBinary() (data []byte, err error) {
+	return json.Marshal(&b)
+}
+
+func (b *BattleReport) UnmarshalBinary(data []byte) error {
+	return json.Unmarshal(data, b)
+}
diff --git a/internal/model/game/battle_test.go b/internal/model/game/battle_test.go
index d40cead..f92d788 100644
--- a/internal/model/game/battle_test.go
+++ b/internal/model/game/battle_test.go
@@ -1,6 +1,7 @@
 package game_test
 
 import (
+	"slices"
 	"testing"
 
 	"github.com/iliadenisov/galaxy/internal/model/game"
@@ -161,3 +162,20 @@ func TestFilterBattleOpponents(t *testing.T) {
 	assert.True(t, game.FilterBattleOpponents(g, 1, 3, cacheShipGroupRaceID, cacheRelation, cacheShipClass, cacheProbability))
 	assert.NotContains(t, cacheProbability[1], 3)
 }
+
+func TestSlicesDeleteFunc(t *testing.T) {
+	type Container struct {
+		S []int
+	}
+	c := Container{S: []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}}
+	r1 := slices.DeleteFunc(c.S, func(e int) bool { return e%2 != 0 })
+	assert.Len(t, r1, 5)
+	for i := range r1 {
+		assert.Equal(t, i*2, r1[i], "elem #%d", i)
+		assert.Equal(t, i*2, c.S[i], "elem #%d", i)
+	}
+	assert.Len(t, c.S, 10)
+	for i := len(r1); i < len(c.S); i++ {
+		assert.Equal(t, 0, c.S[i], "elem #%d", i)
+	}
+}
diff --git a/internal/repo/game.go b/internal/repo/game.go
index 48cedd6..0b74119 100644
--- a/internal/repo/game.go
+++ b/internal/repo/game.go
@@ -2,10 +2,9 @@ package repo
 
 /*
     /state.json
-	/000/state.json
-	/000/race/{UUID}/order/001.json
-	/000/race/{UUID}/report.json
-	/000/battle/{planet_UUID}
+	/0001/state.json
+	/0001/race/{UUID}/report.json
+	/0001/battle/{UUID}.json
 */
 
 import (
@@ -23,7 +22,7 @@ func (r *repo) SaveTurn(t uint, g *game.Game) error {
 }
 
 func saveTurn(s Storage, t uint, g *game.Game) error {
-	path := fmt.Sprintf("%03d/state.json", t)
+	path := fmt.Sprintf("%s/state.json", turnDir(t))
 	exist, err := s.Exists(path)
 	if err != nil {
 		return NewStorageError(err)
@@ -86,3 +85,26 @@ func loadState(s Storage, locked bool) (*game.Game, error) {
 	}
 	return g, nil
 }
+
+func (r *repo) SaveBattle(t uint, b *game.BattleReport) error {
+	return saveBattle(r.s, t, b)
+}
+
+func saveBattle(s Storage, t uint, b *game.BattleReport) error {
+	path := fmt.Sprintf("%s/battle/%s.json", turnDir(t), b.ID)
+	exist, err := s.Exists(path)
+	if err != nil {
+		return NewStorageError(err)
+	}
+	if exist {
+		return NewStateError(fmt.Sprintf("battle %s for turn %d already has been saved", b.ID, t))
+	}
+	if err := s.Write(path, b); err != nil {
+		return NewStorageError(err)
+	}
+	return nil
+}
+
+func turnDir(t uint) string {
+	return fmt.Sprintf("%04d", t)
+}