diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index eab5803b4..ef5b8c1a2 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -201,7 +201,6 @@ Style/GlobalVars:
     - src/test/others/testArgs.rb
     - src/test/others/testCard.rb
     - src/dice/AddDice.rb
-    - src/dice/RerollDice.rb
     - src/diceBot/RecordOfSteam.rb
     - src/diceBot/TokumeiTenkousei.rb
     - src/diceBot/BattleTech.rb
diff --git a/src/dice/RerollDice.rb b/src/dice/RerollDice.rb
index c18270654..6ab919e9f 100644
--- a/src/dice/RerollDice.rb
+++ b/src/dice/RerollDice.rb
@@ -1,5 +1,27 @@
 # -*- coding: utf-8 -*-
 
+require "utils/normalize"
+require "utils/format"
+
+# 個数振り足しダイス
+#
+# ダイスを振り、条件を満たした出目の個数だけダイスを振り足す。振り足しがなくなるまでこれを繰り返す。
+# 成功条件を満たす出目の個数を調べ、成功数を表示する。
+#
+# 例
+#   2R6+1R10[>3]>=5
+#   2R6+1R10>=5@>3
+#
+# 振り足し条件は角カッコかコマンド末尾の @ で指定する。
+# [>3] の場合、3より大きい出目が出たら振り足す。
+# [3] のように数値のみ指定されている場合、成功条件の比較演算子を流用する。
+# 上記の例の時、出目が
+#   "2R6"  -> [5,6] [5,4] [1,3]
+#   "1R10" -> [9] [1]
+# だとすると、 >=5 に該当するダイスは5つなので成功数5となる。
+#
+# 成功条件が書かれていない場合、成功数0として扱う。
+# 振り足し条件が数値のみ指定されている場合、比較演算子は >= が指定されたとして振舞う。
 class RerollDice
   def initialize(bcdice, diceBot)
     @bcdice = bcdice
@@ -7,137 +29,206 @@ def initialize(bcdice, diceBot)
     @nick_e = @bcdice.nick_e
   end
 
-  ####################        個数振り足しダイス     ########################
   def rollDice(string)
-    output = ''
-
-    begin
-      output = rollDiceCatched(string)
-    rescue StandardError => e
-      output = "#{string} ＞ " + e.to_s
+    unless parse(string)
+      return nil
     end
 
-    return "#{@nick_e}: #{output}"
-  end
-
-  def rollDiceCatched(string)
-    debug('RerollDice.rollDice string', string)
-    string = string.strip
-
-    m = /^S?(\d+R\d+(?:\+\d+R\d+)*)(?:\[(\d+)\])?(?:([<>=]+)(\d+))?(?:@(\d+))?$/.match(string)
-    unless m
-      debug("is invaild rdice", string)
-      return '1'
+    unless @reroll_threshold
+      return msg_invalid_reroll_number(string)
     end
 
-    string, braceThreshold, operator, conditionValue, atmarkThreshold = m.captures
-
-    signOfInequality, diff = getCondition(operator, conditionValue)
-    rerollNumber = getRerollNumber(braceThreshold, atmarkThreshold, diff)
-    debug('rerollNumber', rerollNumber)
-
-    debug("diff", diff)
-
-    diceQueue = []
-    string.split("+").each do |xRn|
-      x, n = xRn.split("R").map { |s| s.to_i }
-      checkReRollRule(n, signOfInequality, diff)
+    dice_queue = @notation.split("+").map do |xRn|
+      x, n = xRn.split("R").map(&:to_i)
+      [x, n, 0]
+    end
 
-      diceQueue.push([x, n, 0])
+    unless dice_queue.all? { |d| valid_reroll_rule?(d[1], @reroll_cmp_op, @reroll_threshold) }
+      return msg_invalid_reroll_number(string)
     end
 
-    successCount = 0
-    diceStrList = []
+    success_count = 0
+    dice_str_list = []
     dice_cnt_total = 0
-    numberSpot1Total = 0
-    loopCount = 0
+    one_count = 0
+    loop_count = 0
 
-    while !diceQueue.empty? && @diceBot.should_reroll?(loopCount)
+    dice_total_count = 0
+
+    while !dice_queue.empty? && @diceBot.should_reroll?(loop_count)
       # xRn
-      x, n, depth = diceQueue.shift
-      loopCount += 1
+      x, n, depth = dice_queue.shift
+      loop_count += 1
+      dice_total_count += x
 
-      total, dice_str, numberSpot1, cnt_max, n_max, success, rerollCount =
-        @bcdice.roll(x, n, (@diceBot.sortType & 2), 0, signOfInequality, diff, rerollNumber)
-      debug('bcdice.roll : total, dice_str, numberSpot1, cnt_max, n_max, success, rerollCount',
-            total, dice_str, numberSpot1, cnt_max, n_max, success, rerollCount)
+      dice_list = roll_(x, n)
+      success_count += dice_list.count() { |val| compare(val, @cmp_op, @target_number) } if @cmp_op
+      reroll_count = dice_list.count() { |val| compare(val, @reroll_cmp_op, @reroll_threshold) }
 
-      successCount += success
-      diceStrList.push(dice_str)
-      dice_cnt_total += x
+      dice_str_list.push(dice_list.join(","))
 
       if depth.zero?
-        numberSpot1Total += numberSpot1
+        one_count += dice_list.count(1)
       end
 
-      if rerollCount > 0
-        diceQueue.push([rerollCount, n, depth + 1])
+      if reroll_count > 0
+        dice_queue.push([reroll_count, n, depth + 1])
       end
     end
 
-    output = "#{diceStrList.join(' + ')} ＞ 成功数#{successCount}"
-    string += "[#{rerollNumber}]#{signOfInequality}#{diff}"
+    grich_text = @diceBot.getGrichText(one_count, dice_total_count, success_count)
+
+    sequence = [
+      expr(),
+      dice_str_list.join(" + "),
+      "成功数#{success_count}",
+      trim_prefix(" ＞ ", grich_text),
+    ].compact
 
-    debug("string", string)
-    output += @diceBot.getGrichText(numberSpot1Total, dice_cnt_total, successCount)
+    return "#{@nick_e}: #{sequence.join(' ＞ ')}"
+  end
 
-    output = "(#{string}) ＞ #{output}"
+  private
 
-    if output.length > $SEND_STR_MAX # 長すぎたときの救済
-      output = "(#{string}) ＞ ... ＞ 回転数#{round} ＞ 成功数#{successCount}"
+  # @param command [String]
+  # @return [Boolean]
+  def parse(command)
+    m = /^S?(\d+R\d+(?:\+\d+R\d+)*)(?:\[([<>=]+)?(\d+)\])?(?:([<>=]+)(\d+))?(?:@([<>=]+)?(\d+))?$/.match(command)
+    unless m
+      return false
     end
 
-    return output
+    @notation = m[1]
+    @cmp_op = Normalize.comparison_operator(m[4])
+    @target_number = @cmp_op ? m[5].to_i : nil
+    unless @cmp_op
+      @cmp_op, @target_number = target_from_default()
+    end
+
+    @reroll_cmp_op = decide_reroll_cmp_op(m)
+    @reroll_threshold = decide_reroll_threshold(m[3] || m[7], @target_number)
+
+    return true
   end
 
-  def getCondition(operator, conditionValue)
-    if operator && conditionValue
-      operator = @bcdice.marshalSignOfInequality(operator)
-      conditionValue = conditionValue.to_i
-    elsif (m = /([<>=]+)(\d+)/.match(@diceBot.defaultSuccessTarget))
-      operator = @bcdice.marshalSignOfInequality(m[1])
-      conditionValue = m[2].to_i
+  # @return [Array<(Symbol, Integer)>]
+  # @return [Array<(nil, nil)>]
+  def target_from_default
+    m = /^([<>=]+)(\d+)$/.match(@diceBot.defaultSuccessTarget)
+    unless m
+      return nil, nil
     end
 
-    return operator, conditionValue
+    cmp_op = Normalize.comparison_operator(m[1])
+    target_number = cmp_op ? m[2].to_i : nil
+    return cmp_op, target_number
   end
 
-  def getRerollNumber(braceThreshold, atmarkThreshold, conditionValue)
-    if braceThreshold
-      braceThreshold.to_i
-    elsif atmarkThreshold
-      atmarkThreshold.to_i
+  # @param m [MatchData]
+  # @return [Symbol]
+  def decide_reroll_cmp_op(m)
+    bracket_op = m[2]
+    bracket_number = m[3]
+    at_op = m[6]
+    at_number = m[7]
+    cmp_op = m[4]
+
+    op =
+      if bracket_op && bracket_number
+        bracket_op
+      elsif at_op && at_number
+        at_op
+      else
+        cmp_op
+      end
+
+    Normalize.comparison_operator(op) || :>=
+  end
+
+  # @param captured_threshold [String, nil]
+  # @param target_number [Integer, nil]
+  # @return [Integer]
+  # @return [nil]
+  def decide_reroll_threshold(captured_threshold, target_number)
+    if captured_threshold
+      captured_threshold.to_i
     elsif @diceBot.rerollNumber != 0
       @diceBot.rerollNumber
-    elsif conditionValue
-      conditionValue.to_i
     else
-      raiseErroForJudgeRule()
+      target_number
     end
   end
 
-  def raiseErroForJudgeRule()
-    raise "条件が間違っています。2R6>=5 あるいは 2R6[5] のように振り足し目標値を指定してください。"
+  # @return [String]
+  def expr()
+    reroll_cmp_op_text = @cmp_op != @reroll_cmp_op ? Format.comparison_operator(@reroll_cmp_op) : nil
+    cmp_op_text = Format.comparison_operator(@cmp_op)
+
+    "(#{@notation}[#{reroll_cmp_op_text}#{@reroll_threshold}]#{cmp_op_text}#{@target_number})"
   end
 
-  def checkReRollRule(dice_max, signOfInequality, diff) # 振り足しロールの条件確認
-    valid = true
-
-    case signOfInequality
-    when '<='
-      valid = false if diff >= dice_max
-    when '>='
-      valid = false if diff <= 1
-    when '<>'
-      valid = false if (diff > dice_max) || (diff < 1)
-    when '<'
-      valid = false if diff > dice_max
-    when '>'
-      valid = false if diff < 1
+  # @param command [String]
+  # @return [String]
+  def msg_invalid_reroll_number(command)
+    "#{@nick_e}: #{command} ＞ 条件が間違っています。2R6>=5 あるいは 2R6[5] のように振り足し目標値を指定してください。"
+  end
+
+  # @param sides [Integer]
+  # @param cmp_op [Symbol]
+  # @param reroll_threshold [Integer]
+  # @return [Boolean]
+  def valid_reroll_rule?(sides, cmp_op, reroll_threshold) # 振り足しロールの条件確認
+    case cmp_op
+    when :<=
+      reroll_threshold < sides
+    when :<
+      reroll_threshold <= sides
+    when :>=
+      reroll_threshold > 1
+    when :>
+      reroll_threshold >= 1
+    when :'!='
+      (1..sides).include?(reroll_threshold)
+    else
+      true
     end
+  end
 
-    unless valid
-      raiseErroForJudgeRule()
+  # @param times [Integer]
+  # @param sides [Integer]
+  # @return [Array<Integer>]
+  def roll_(times, sides)
+    _, dice_list, = @bcdice.roll(times, sides, (@diceBot.sortType & 2))
+    dice_list.split(",").map(&:to_i)
+  end
+
+  # @param prefix [String]
+  # @param string [String]
+  # @param [String, nil]
+  def trim_prefix(prefix, string)
+    if string.start_with?(prefix)
+      string = string[prefix.size..-1]
+    end
+
+    if string.empty?
+      nil
+    else
+      string
+    end
+  end
+
+  # 整数を比較する
+  # Ruby 1.8のケア用
+  #
+  # @param lhs [Integer]
+  # @param op [Symbol]
+  # @param rhs [Integer]
+  # @return [Boolean]
+  def compare(lhs, op, rhs)
+    if op == :'!='
+      lhs != rhs
+    else
+      lhs.send(op, rhs)
     end
   end
 end
diff --git a/src/test/data/None.txt b/src/test/data/None.txt
index a9c69b472..8462d913a 100644
--- a/src/test/data/None.txt
+++ b/src/test/data/None.txt
@@ -682,6 +682,12 @@ DiceBot : (2R6[3]>=3) ＞ 6,1 + 3 + 1 ＞ 成功数2
 rand:6/6,1/6,3/6,1/6
 ============================
 input:
+2R6>3
+output:
+DiceBot : (2R6[3]>3) ＞ 6,1 + 3 ＞ 成功数1
+rand:6/6,1/6,3/6
+============================
+input:
 12R6>=6
 output:
 DiceBot : (12R6[6]>=6) ＞ 4,1,5,4,3,2,5,1,6,3,2,5 + 5 ＞ 成功数1
@@ -748,6 +754,36 @@ DiceBot : (2R4+2R6[4]>=4) ＞ 4,3 + 3,5 + 1 + 2 ＞ 成功数2
 rand:4/4,3/4,3/6,5/6,1/4,2/6
 ============================
 input:
+2R4+2R6[>4]>=4
+output:
+DiceBot : (2R4+2R6[>4]>=4) ＞ 4,3 + 3,5 + 2 ＞ 成功数2
+rand:4/4,3/4,3/6,5/6,2/6
+============================
+input:
+2R4+2R6>=4@>4
+output:
+DiceBot : (2R4+2R6[>4]>=4) ＞ 4,3 + 3,5 + 2 ＞ 成功数2
+rand:4/4,3/4,3/6,5/6,2/6
+============================
+input:
+2R4+2R6[<=2]>=4
+output:
+DiceBot : (2R4+2R6[<=2]>=4) ＞ 4,2 + 3,5 + 2 + 4 ＞ 成功数3
+rand:4/4,2/4,3/6,5/6,2/4,4/4
+============================
+input:
+2R4+2R6>=4@<=2
+output:
+DiceBot : (2R4+2R6[<=2]>=4) ＞ 4,2 + 3,5 + 2 + 4 ＞ 成功数3
+rand:4/4,2/4,3/6,5/6,2/4,4/4
+============================
+input:
+2R4+2R6[<>4]>=4
+output:
+DiceBot : (2R4+2R6[<>4]>=4) ＞ 4,2 + 3,5 + 4 + 4,4 ＞ 成功数5
+rand:4/4,2/4,3/6,5/6,4/4,4/6,4/6
+============================
+input:
 134 数値だけには反応しない
 output:
 rand:
@@ -998,15 +1034,21 @@ DiceBot : 2R6 ＞ 条件が間違っています。2R6>=5 あるいは 2R6[5] 
 rand:
 ============================
 input:
+2R6<=7 無限に振り足ししてしまう
+output:
+DiceBot : 2R6<=7 ＞ 条件が間違っています。2R6>=5 あるいは 2R6[5] のように振り足し目標値を指定してください。
+rand:
+============================
+input:
 2R6[3]
 output:
-DiceBot : (2R6[3]) ＞ 3,2 + 1 ＞ 成功数0
+DiceBot : (2R6[>=3]) ＞ 3,2 + 1 ＞ 成功数0
 rand:3/6,2/6,1/6
 ============================
 input:
 S2R6[3]
 output:
-DiceBot : (2R6[3]) ＞ 3,2 + 1 ＞ 成功数0###secret dice###
+DiceBot : (2R6[>=3]) ＞ 3,2 + 1 ＞ 成功数0###secret dice###
 rand:3/6,2/6,1/6
 ============================
 input: