diff --git a/cmd/gmars/main.go b/cmd/gmars/main.go
index 5df4231..703a45a 100644
--- a/cmd/gmars/main.go
+++ b/cmd/gmars/main.go
@@ -46,53 +46,49 @@ func main() {
 
 	args := flag.Args()
 
-	if *assembleFlag {
-		if len(args) != 1 {
-			fmt.Println("wrong number of arguments")
-			os.Exit(1)
-		}
-	} else if len(args) < 2 || len(args) > 2 {
-		fmt.Println("only 2 warrior battles supported")
+	if len(args) > 2 {
+		fmt.Fprintf(os.Stderr, "only 2 warrior battles supported")
 		os.Exit(1)
 	}
 
-	w1file, err := os.Open(args[0])
-	if err != nil {
-		fmt.Printf("error opening warrior file '%s': %s\n", args[0], err)
-		os.Exit(1)
+	warriors := make([]gmars.WarriorData, 0)
+	for _, arg := range args {
+		in, err := os.Open(arg)
+		if err != nil {
+			fmt.Printf("error opening warrior file '%s': %s\n", arg, err)
+			os.Exit(1)
+		}
+		defer in.Close()
+
+		warrior, err := gmars.CompileWarrior(in, config)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error parsing warrior file '%s': %s\n", arg, err)
+			os.Exit(1)
+		}
+
+		warriors = append(warriors, warrior)
 	}
-	defer w1file.Close()
-	w1data, err := gmars.CompileWarrior(w1file, config)
-	if err != nil {
-		fmt.Printf("error parsing warrior file '%s': %s\n", args[0], err)
+
+	if len(warriors) == 0 {
+		fmt.Fprintf(os.Stderr, "no warriors specified\n")
 		os.Exit(1)
 	}
-	w1file.Close()
-
 	if *assembleFlag {
 		sim, err := gmars.NewSimulator(config)
 		if err != nil {
 			fmt.Printf("error creating sim: %s", err)
 		}
-		w1, err := sim.AddWarrior(&w1data)
-		if err != nil {
-			fmt.Printf("error loading warrior: %s", err)
+
+		for _, warriorData := range warriors {
+			w, err := sim.AddWarrior(&warriorData)
+			if err != nil {
+				fmt.Printf("error loading warrior: %s", err)
+			}
+			fmt.Println(w.LoadCode())
 		}
-		fmt.Println(w1.LoadCode())
-		return
-	}
 
-	w2file, err := os.Open(args[1])
-	if err != nil {
-		fmt.Printf("error opening warrior file '%s': %s\n", args[1], err)
-		os.Exit(1)
-	}
-	defer w1file.Close()
-	w2data, err := gmars.CompileWarrior(w2file, config)
-	if err != nil {
-		fmt.Printf("error parsing warrior file '%s': %s\n", args[1], err)
+		return
 	}
-	w1file.Close()
 
 	rounds := *roundFlag
 
@@ -117,42 +113,58 @@ func main() {
 			w2start = rand.Intn(int(startRange)+1) + int(minStart)
 		}
 
-		w1, err := sim.AddWarrior(&w1data)
+		w1, err := sim.AddWarrior(&warriors[0])
 		if err != nil {
 			fmt.Printf("error adding warrior 1: %s", err)
+			os.Exit(1)
 		}
 		err = sim.SpawnWarrior(0, 0)
 		if err != nil {
 			fmt.Printf("error adding warrior 1: %s", err)
+			os.Exit(1)
 		}
 
-		w2, err := sim.AddWarrior(&w2data)
-		if err != nil {
-			fmt.Printf("error adding warrior 2: %s", err)
-		}
-		err = sim.SpawnWarrior(1, gmars.Address(w2start))
-		if err != nil {
-			fmt.Printf("error spawning warrior 1: %s", err)
+		var w2 gmars.Warrior
+		if len(warriors) > 1 {
+			w, err := sim.AddWarrior(&warriors[1])
+			if err != nil {
+				fmt.Printf("error adding warrior 2: %s", err)
+				os.Exit(1)
+			}
+			err = sim.SpawnWarrior(1, gmars.Address(w2start))
+			if err != nil {
+				fmt.Printf("error spawning warrior 1: %s", err)
+				os.Exit(1)
+			}
+			w2 = w
 		}
 
 		sim.Run()
 
-		if w1.Alive() {
-			if w2.Alive() {
-				w1tie += 1
-			} else {
+		if len(warriors) == 1 {
+			if w1.Alive() {
 				w1win += 1
 			}
-		}
-
-		if w2.Alive() {
+		} else if len(warriors) == 2 {
 			if w1.Alive() {
-				w2tie += 1
-			} else {
-				w2win += 1
+				if w2.Alive() {
+					w1tie += 1
+				} else {
+					w1win += 1
+				}
+			}
+
+			if w2.Alive() {
+				if w1.Alive() {
+					w2tie += 1
+				} else {
+					w2win += 1
+				}
 			}
 		}
 	}
 	fmt.Printf("%d %d\n", w1win, w1tie)
-	fmt.Printf("%d %d\n", w2win, w2tie)
+	if len(warriors) > 1 {
+		fmt.Printf("%d %d\n", w2win, w2tie)
+	}
 }
diff --git a/cmd/vmars/draw.go b/cmd/vmars/draw.go
index 10228ac..eec0cf1 100644
--- a/cmd/vmars/draw.go
+++ b/cmd/vmars/draw.go
@@ -94,28 +94,30 @@ func (g *Game) Draw(screen *ebiten.Image) {
 
 	// draw results if finished
 	if g.finished {
-		w1a := g.sim.GetWarrior(0).Alive()
-		w2a := g.sim.GetWarrior(1).Alive()
-
-		if w1a || w2a {
-
-			var msg string
-			op = &text.DrawOptions{}
-			op.GeoM.Translate(115, 465)
-			if w1a && w2a {
-				op.ColorScale = warriorColors[0]
-				msg = "tie"
-			} else if w1a {
-				op.ColorScale = warriorColors[1]
-				msg = fmt.Sprintf("%s wins", g.sim.GetWarrior(0).Name())
-			} else if w2a {
-				op.ColorScale = warriorColors[2]
-				msg = fmt.Sprintf("%s wins", g.sim.GetWarrior(1).Name())
+		if g.sim.WarriorCount() > 1 {
+			w1a := g.sim.GetWarrior(0).Alive()
+			w2a := g.sim.GetWarrior(1).Alive()
+
+			if w1a || w2a {
+
+				var msg string
+				op = &text.DrawOptions{}
+				op.GeoM.Translate(115, 465)
+				if w1a && w2a {
+					op.ColorScale = warriorColors[0]
+					msg = "tie"
+				} else if w1a {
+					op.ColorScale = warriorColors[1]
+					msg = fmt.Sprintf("%s wins", g.sim.GetWarrior(0).Name())
+				} else if w2a {
+					op.ColorScale = warriorColors[2]
+					msg = fmt.Sprintf("%s wins", g.sim.GetWarrior(1).Name())
+				}
+				text.Draw(screen, msg, &text.GoTextFace{
+					Source: mplusFaceSource,
+					Size:   10,
+				}, op)
 			}
-			text.Draw(screen, msg, &text.GoTextFace{
-				Source: mplusFaceSource,
-				Size:   10,
-			}, op)
 		}
 	} else if !g.running {
 		op = &text.DrawOptions{}
diff --git a/cmd/vmars/game.go b/cmd/vmars/game.go
index a50e4bd..b66df49 100644
--- a/cmd/vmars/game.go
+++ b/cmd/vmars/game.go
@@ -45,16 +45,17 @@ func (g *Game) handleInput() {
 		g.sim.Reset()
 		g.sim.SpawnWarrior(0, 0)
 
-		w2start := g.fixedStart
-		if w2start == 0 {
-			minStart := 2 * g.config.Length
-			maxStart := g.config.CoreSize - g.config.Length - 1
-			startRange := maxStart - minStart
-			w2start = rand.Intn(int(startRange)+1) + int(minStart)
+		if g.sim.WarriorCount() > 1 {
+			w2start := g.fixedStart
+			if w2start == 0 {
+				minStart := 2 * g.config.Length
+				maxStart := g.config.CoreSize - g.config.Length - 1
+				startRange := maxStart - minStart
+				w2start = rand.Intn(int(startRange)+1) + int(minStart)
+			}
+			g.sim.SpawnWarrior(1, gmars.Address(w2start))
 		}
 
-		g.sim.SpawnWarrior(1, gmars.Address(w2start))
-
 		g.finished = false
 	} else if inpututil.IsKeyJustPressed(ebiten.KeyDown) {
 		g.slowDown()
@@ -78,7 +79,9 @@ func (g *Game) runCycle() {
 		return
 	}
 
-	if g.sim.WarriorLivingCount() > 1 && g.sim.CycleCount() < g.sim.MaxCycles() {
+	count := g.sim.WarriorCount()
+	living := g.sim.WarriorLivingCount()
+	if ((count > 1 && living > 1) || living > 0) && g.sim.CycleCount() < g.sim.MaxCycles() {
 		g.sim.RunCycle()
 	} else {
 		g.finished = true
diff --git a/cmd/vmars/main.go b/cmd/vmars/main.go
index c07fab0..87b4b5a 100644
--- a/cmd/vmars/main.go
+++ b/cmd/vmars/main.go
@@ -89,35 +89,28 @@ func main() {
 
 	args := flag.Args()
 
-	if len(args) < 2 || len(args) > 2 {
-		fmt.Println("only 2 warrior battles supported")
+	if len(args) > 2 {
+		fmt.Fprintf(os.Stderr, "only 2 warrior battles supported")
 		os.Exit(1)
 	}
 
-	w1file, err := os.Open(args[0])
-	if err != nil {
-		fmt.Printf("error opening warrior file '%s': %s\n", args[0], err)
-		os.Exit(1)
-	}
-	defer w1file.Close()
-	w1data, err := gmars.CompileWarrior(w1file, config)
-	if err != nil {
-		fmt.Printf("error parsing warrior file '%s': %s\n", args[0], err)
-		os.Exit(1)
-	}
-	w1file.Close()
+	warriors := make([]gmars.WarriorData, 0)
+	for _, arg := range args {
+		in, err := os.Open(arg)
+		if err != nil {
+			fmt.Printf("error opening warrior file '%s': %s\n", arg, err)
+			os.Exit(1)
+		}
+		defer in.Close()
 
-	w2file, err := os.Open(args[1])
-	if err != nil {
-		fmt.Printf("error opening warrior file '%s': %s\n", args[1], err)
-		os.Exit(1)
-	}
-	defer w1file.Close()
-	w2data, err := gmars.CompileWarrior(w2file, config)
-	if err != nil {
-		fmt.Printf("error parsing warrior file '%s': %s\n", args[1], err)
+		warrior, err := gmars.CompileWarrior(in, config)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error parsing warrior file '%s': %s\n", arg, err)
+			os.Exit(1)
+		}
+
+		warriors = append(warriors, warrior)
 	}
-	w1file.Close()
 
 	sim, err := gmars.NewReportingSimulator(config)
 	if err != nil {
@@ -130,19 +123,23 @@ func main() {
 	rec.SetRecordRead(*showReadFlag)
 	sim.AddReporter(rec)
 
-	w2start := *fixedFlag
-	if w2start == 0 {
-		minStart := 2 * config.Length
-		maxStart := config.CoreSize - config.Length - 1
-		startRange := maxStart - minStart
-		w2start = rand.Intn(int(startRange)+1) + int(minStart)
+	sim.AddWarrior(&warriors[0])
+	if len(warriors) > 1 {
+		sim.AddWarrior(&warriors[1])
 	}
 
-	sim.AddWarrior(&w1data)
-	sim.AddWarrior(&w2data)
-
 	sim.SpawnWarrior(0, 0)
-	sim.SpawnWarrior(1, gmars.Address(w2start))
+
+	if len(warriors) > 1 {
+		w2start := *fixedFlag
+		if w2start == 0 {
+			minStart := 2 * config.Length
+			maxStart := config.CoreSize - config.Length - 1
+			startRange := maxStart - minStart
+			w2start = rand.Intn(int(startRange)+1) + int(minStart)
+		}
+		sim.SpawnWarrior(1, gmars.Address(w2start))
+	}
 
 	game := &Game{
 		sim:        sim,
@@ -153,7 +150,11 @@ func main() {
 	}
 
 	ebiten.SetWindowSize(screenWidth, screenHeight)
-	ebiten.SetWindowTitle(fmt.Sprintf("gMARS - '%s' vs '%s'", w1data.Name, w2data.Name))
+	if len(warriors) > 1 {
+		ebiten.SetWindowTitle(fmt.Sprintf("gMARS - '%s' vs '%s'", warriors[0].Name, warriors[1].Name))
+	} else {
+		ebiten.SetWindowTitle(fmt.Sprintf("gMARS - '%s'", warriors[0].Name))
+	}
 	if err := ebiten.RunGame(game); err != nil {
 		log.Fatal(err)
 	}