diff --git a/src/entity/hand.go b/src/entity/hand.go
index 4dbc8ba..c59e759 100644
--- a/src/entity/hand.go
+++ b/src/entity/hand.go
@@ -1,5 +1,9 @@
 package entity
 
+import (
+	"sort"
+)
+
 type Hand struct {
 	Public  []Card
 	Private []Card
@@ -15,3 +19,38 @@ func (hand *Hand) Push(card Card) {
 func (hand Hand) Len() int {
 	return len(hand.Public) + len(hand.Private)
 }
+
+func (hand Hand) AllCards() []Card {
+	allcards := make([]Card, 0, len(hand.Public)+len(hand.Private))
+	for _, cards := range [][]Card{hand.Public, hand.Private} {
+		allcards = append(allcards, cards...)
+	}
+	return allcards
+}
+
+func (hand Hand) Flush() bool {
+	suit := -1
+	for _, card := range hand.AllCards() {
+		if suit == -1 {
+			suit = card.Suit
+		} else if suit != card.Suit {
+			return false
+		}
+	}
+	return suit != -1
+}
+
+func (hand Hand) Straight() bool {
+	cards := hand.AllCards()
+	values := make([]int, 0, len(cards))
+	for _, card := range cards {
+		values = append(values, card.Value)
+	}
+	sort.Ints(values)
+	for i := 1; i < len(values); i++ {
+		if values[i-1]+1 != values[i] {
+			return false
+		}
+	}
+	return len(values) > 1
+}
diff --git a/src/entity/hand_test.go b/src/entity/hand_test.go
new file mode 100644
index 0000000..7da671f
--- /dev/null
+++ b/src/entity/hand_test.go
@@ -0,0 +1,107 @@
+package entity
+
+import (
+	"testing"
+)
+
+func TestHandAllCards(t *testing.T) {
+	t.Run("all pub", func(t *testing.T) {
+		hand := Hand{
+			Public: []Card{
+				Card{Value: 1},
+				Card{Value: 2},
+			},
+		}
+		all := hand.AllCards()
+		if len(all) != 2 {
+			t.Fatal(all)
+		}
+	})
+
+	t.Run("all pri", func(t *testing.T) {
+		hand := Hand{
+			Private: []Card{
+				Card{Value: 1},
+				Card{Value: 2},
+			},
+		}
+		all := hand.AllCards()
+		if len(all) != 2 {
+			t.Fatal(all)
+		}
+	})
+
+	t.Run("both", func(t *testing.T) {
+		hand := Hand{
+			Public: []Card{
+				Card{Value: 3},
+				Card{Value: 4},
+			},
+			Private: []Card{
+				Card{Value: 1},
+				Card{Value: 2},
+			},
+		}
+		all := hand.AllCards()
+		if len(all) != 4 {
+			t.Fatal(all)
+		}
+	})
+}
+
+func TestHandStraight(t *testing.T) {
+	cases := map[string]struct {
+		public  []Card
+		private []Card
+		want    bool
+	}{
+		"empty": {
+			want: false,
+		},
+		"one public card": {
+			public: []Card{Card{Value: 3}},
+			want:   false,
+		},
+		"one private card": {
+			private: []Card{Card{Value: 3}},
+			want:    false,
+		},
+		"two public card nonseq": {
+			public: []Card{Card{Value: 3}, Card{Value: 1}},
+			want:   false,
+		},
+		"two private card nonseq": {
+			private: []Card{Card{Value: 3}, Card{Value: 1}},
+			want:    false,
+		},
+		"one public card one private card nonseq": {
+			public:  []Card{Card{Value: 3}},
+			private: []Card{Card{Value: 1}},
+			want:    false,
+		},
+		"two public card seq": {
+			public: []Card{Card{Value: 3}, Card{Value: 2}},
+			want:   true,
+		},
+		"two private card seq": {
+			private: []Card{Card{Value: 3}, Card{Value: 2}},
+			want:    true,
+		},
+		"one public card one private card seq": {
+			public:  []Card{Card{Value: 2}},
+			private: []Card{Card{Value: 1}},
+			want:    true,
+		},
+	}
+
+	for name, d := range cases {
+		c := d
+		t.Run(name, func(t *testing.T) {
+			hand := Hand{Public: c.public, Private: c.private}
+			got := hand.Straight()
+			if got != c.want {
+				t.Fatal(c.want, got)
+			}
+		})
+	}
+}
diff --git a/src/game/rule/operation/hand.go b/src/game/rule/operation/hand.go
new file mode 100644
index 0000000..223337e
--- /dev/null
+++ b/src/game/rule/operation/hand.go
@@ -0,0 +1,135 @@
+package operation
+
+import (
+	"local/sandbox/cards/src/entity"
+	"sort"
+)
+
+func royalFlush(game *entity.Game, _ interface{}) int {
+	hand := getHand(game)
+	if !hand.Flush() || !hand.Straight() {
+		return 0
+	}
+	for _, card := range hand.AllCards() {
+		if card.Value < 11 {
+			return 0
+		}
+	}
+	return 1
+}
+
+func straightFlush(game *entity.Game, _ interface{}) int {
+	hand := getHand(game)
+	if !hand.Flush() || !hand.Straight() {
+		return 0
+	}
+	biggest := 0
+	for _, card := range hand.AllCards() {
+		if card.Value > biggest {
+			biggest = card.Value
+		}
+	}
+	return biggest
+}
+
+func fourOfAKind(game *entity.Game, _ interface{}) int {
+	hand := getHand(game)
+	counts := counts(hand)
+	best := entity.Card{}
+	high := entity.Card{}
+	for k, v := range counts {
+		if v >= 4 && k.Value > best.Value {
+			best = k
+		}
+		if v != 4 && k.Value > high.Value {
+			high = k
+		}
+	}
+	if best.Value == 0 {
+		return 0
+	}
+	return best.Value*100 + high.Value
+}
+
+func fullHouse(game *entity.Game, _ interface{}) int {
+	hand := getHand(game)
+	counts := counts(hand)
+	trio := entity.Card{}
+	duo := entity.Card{}
+	for k, v := range counts {
+		if v == 3 && k.Value > trio.Value {
+			trio = k
+		}
+		if v == 2 && k.Value > duo.Value {
+			duo = k
+		}
+	}
+	if trio.Value == 0 || duo.Value == 0 {
+		return 0
+	}
+	return trio.Value*100 + duo.Value
+}
+
+func flush(game *entity.Game, _ interface{}) int {
+	hand := getHand(game)
+	if !hand.Flush() {
+		return 0
+	}
+	values := make([]int, 0)
+	for _, card := range hand.AllCards() {
+		values = append(values, card.Value)
+	}
+	sort.Ints(values)
+	rank := 0
+	for i := len(values) - 1; i >= 0; i-- {
+		rank = rank*100 + values[i]
+	}
+	return rank
+}
+
+func straight(game *entity.Game, _ interface{}) int {
+	hand := getHand(game)
+	if !hand.Straight() {
+		return 0
+	}
+	big := 0
+	for _, card := range hand.AllCards() {
+		if card.Value > big {
+			big = card.Value
+		}
+	}
+	return big
+}
+
+func threeOfAKind(game *entity.Game, _ interface{}) int {
+	panic("not impl")
+}
+
+func twoPair(game *entity.Game, _ interface{}) int {
+	panic("not impl")
+}
+
+func pair(game *entity.Game, _ interface{}) int {
+	panic("not impl")
+}
+
+func highCard(game *entity.Game, _ interface{}) int {
+	panic("not impl")
+}
+
+func getHand(game *entity.Game) entity.Hand {
+	player := game.Players[game.Current.Turn]
+	return player.Hand
+}
+
+func counts(hand entity.Hand) map[entity.Card]int {
+	cards := hand.AllCards()
+	m := make(map[entity.Card]int, len(cards))
+	for _, card := range cards {
+		if _, ok := m[card]; !ok {
+			m[card] = 0
+		}
+		m[card] += 1
+	}
+	return m
+}
diff --git a/src/game/rule/operation/hand_test.go b/src/game/rule/operation/hand_test.go
new file mode 100644
index 0000000..60d8212
--- /dev/null
+++ b/src/game/rule/operation/hand_test.go
@@ -0,0 +1,279 @@
+package operation
+
+import (
+	"local/sandbox/cards/src/entity"
+	"testing"
+)
+
+type testHandCase struct {
+	public  []entity.Card
+	private []entity.Card
+	want    int
+}
+
+func TestStraight(t *testing.T) {
+	cases := map[string]testHandCase{
+		"no cards": {
+			want: 0,
+		},
+		"straight big 3": {
+			public: []entity.Card{
+				entity.Card{Value: 11},
+				entity.Card{Value: 12},
+				entity.Card{Value: 13},
+			},
+			want: 13,
+		},
+		"straight sm 3": {
+			public: []entity.Card{
+				entity.Card{Value: 1},
+				entity.Card{Value: 2},
+				entity.Card{Value: 3},
+			},
+			want: 3,
+		},
+		"straight sm 2": {
+			public: []entity.Card{
+				entity.Card{Value: 1},
+				entity.Card{Value: 2},
+			},
+			want: 2,
+		},
+		"not a straight": {
+			public: []entity.Card{
+				entity.Card{Value: 1},
+				entity.Card{Value: 3},
+			},
+			want: 0,
+		},
+	}
+
+	for name, d := range cases {
+		testHand(t, name, straight, d.public, d.private, d.want)
+	}
+}
+
+func TestFlush(t *testing.T) {
+	cases := map[string]testHandCase{
+		"no cards": {
+			want: 0,
+		},
+		"not a flush": {
+			public: []entity.Card{
+				entity.Card{Value: 1, Suit: 0},
+				entity.Card{Value: 2, Suit: 1},
+			},
+			want: 0,
+		},
+		"big, big, small, small flush": {
+			public: []entity.Card{
+				entity.Card{Value: 12},
+				entity.Card{Value: 10},
+				entity.Card{Value: 2},
+				entity.Card{Value: 1},
+			},
+			want: 12100201,
+		},
+		"small, small flush": {
+			public: []entity.Card{
+				entity.Card{Value: 2},
+				entity.Card{Value: 1},
+			},
+			want: 201,
+		},
+		"big, small flush": {
+			public: []entity.Card{
+				entity.Card{Value: 11},
+				entity.Card{Value: 1},
+			},
+			want: 1101,
+		},
+		"big, big flush": {
+			public: []entity.Card{
+				entity.Card{Value: 11},
+				entity.Card{Value: 12},
+			},
+			want: 1211,
+		},
+	}
+
+	for name, d := range cases {
+		testHand(t, name, flush, d.public, d.private, d.want)
+	}
+}
+
+func TestFullHouse(t *testing.T) {
+	cases := map[string]testHandCase{
+		"no cards": {
+			want: 0,
+		},
+		"10 > 11": {
+			public: []entity.Card{
+				entity.Card{Value: 11},
+				entity.Card{Value: 11},
+				entity.Card{Value: 10},
+				entity.Card{Value: 10},
+				entity.Card{Value: 10},
+			},
+			want: 1011,
+		},
+		"five of a kind": {
+			public: []entity.Card{
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+			},
+			want: 0,
+		},
+		"two pair": {
+			public: []entity.Card{
+				entity.Card{Value: 4},
+				entity.Card{Value: 4},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 6},
+			},
+			want: 0,
+		},
+	}
+
+	for name, d := range cases {
+		testHand(t, name, fullHouse, d.public, d.private, d.want)
+	}
+}
+
+func TestFourOfAKind(t *testing.T) {
+	cases := map[string]testHandCase{
+		"no cards": {
+			want: 0,
+		},
+		"one card": {
+			public: []entity.Card{
+				entity.Card{Value: 5},
+			},
+			want: 0,
+		},
+		"two cards": {
+			public: []entity.Card{
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+			},
+			want: 0,
+		},
+		"three cards": {
+			public: []entity.Card{
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+			},
+			want: 0,
+		},
+		"four cards": {
+			public: []entity.Card{
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+			},
+			want: 500,
+		},
+		"five cards": {
+			public: []entity.Card{
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+				entity.Card{Value: 5},
+			},
+			want: 505,
+		},
+	}
+
+	for name, d := range cases {
+		testHand(t, name, fourOfAKind, d.public, d.private, d.want)
+	}
+}
+
+func TestStraightFlush(t *testing.T) {
+	cases := map[string]testHandCase{
+		"no cards": {
+			want: 0,
+		},
+		"one nonroyal cards": {
+			public: []entity.Card{entity.Card{Value: 5}},
+			want:   0,
+		},
+		"one royal cards": {
+			public: []entity.Card{entity.Card{Value: 12}},
+			want:   0,
+		},
+		"two nonroyal cards": {
+			public: []entity.Card{entity.Card{Value: 5}, entity.Card{Value: 6}},
+			want:   6,
+		},
+		"twe royal cards": {
+			public: []entity.Card{entity.Card{Value: 12}, entity.Card{Value: 13}},
+			want:   13,
+		},
+		"twe mix cards": {
+			public: []entity.Card{entity.Card{Value: 11}, entity.Card{Value: 10}},
+			want:   11,
+		},
+	}
+
+	for name, d := range cases {
+		testHand(t, name, straightFlush, d.public, d.private, d.want)
+	}
+}
+
+func TestRoyalFlush(t *testing.T) {
+	cases := map[string]testHandCase{
+		"no cards": {
+			want: 0,
+		},
+		"one nonroyal cards": {
+			public: []entity.Card{entity.Card{Value: 5}},
+			want:   0,
+		},
+		"one royal cards": {
+			public: []entity.Card{entity.Card{Value: 12}},
+			want:   0,
+		},
+		"two nonroyal cards": {
+			public: []entity.Card{entity.Card{Value: 5}, entity.Card{Value: 6}},
+			want:   0,
+		},
+		"twe royal cards": {
+			public: []entity.Card{entity.Card{Value: 12}, entity.Card{Value: 13}},
+			want:   1,
+		},
+		"twe mix cards": {
+			public: []entity.Card{entity.Card{Value: 11}, entity.Card{Value: 10}},
+			want:   0,
+		},
+	}
+
+	for name, d := range cases {
+		testHand(t, name, royalFlush, d.public, d.private, d.want)
+	}
+}
+
+func testHand(t *testing.T, name string, foo Int, public []entity.Card, private []entity.Card, want int) {
+	t.Run(name, func(t *testing.T) {
+		hand := entity.Hand{
+			Public:  public,
+			Private: private,
+		}
+		game := &entity.Game{
+			Players: []entity.Player{
+				entity.Player{Hand: hand},
+			},
+		}
+		got := foo(game, nil)
+		if got != want {
+			t.Fatal(want, got)
+		}
+	})
+}
diff --git a/src/game/rule/operation/int.go b/src/game/rule/operation/int.go
index c3cd13c..99e20aa 100644
--- a/src/game/rule/operation/int.go
+++ b/src/game/rule/operation/int.go
@@ -1,5 +1,41 @@
 package operation
 
-import "local/sandbox/cards/src/entity"
+import (
+	"encoding/json"
+	"errors"
+	"local/sandbox/cards/src/entity"
+)
 
 type Int func(*entity.Game, interface{}) int
+
+var intStringified = map[string]Int{
+	"royalFlush":    royalFlush,
+	"straightFlush": straightFlush,
+	"fourOfAKind":   fourOfAKind,
+	"fullHouse":     fullHouse,
+	"flush":         flush,
+	"straight":      straight,
+	"threeOfAKind":  threeOfAKind,
+	"twoPair":       twoPair,
+	"pair":          pair,
+	"highCard":      highCard,
+}
+
+func (foo *Int) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+
+	return foo.FromString(s)
+}
+
+func (foo *Int) FromString(s string) error {
+	for k, v := range intStringified {
+		if k == s {
+			*foo = v
+			return nil
+		}
+	}
+	return errors.New("unknown int method " + s)
+}