Sudden death function/loop issue

import random
import time
import math
import sys

strength_mod = 0
skill_mod = 0
counter = 215
#counter set to 215 to make sure code is working and as a build up

def delay_print(s):
    for c in s:
        sys.stdout.write( '%s' % c )
        sys.stdout.flush()
        time.sleep(0.02)

def str_mod(charone_str,chartwo_str):
    if charone_str > chartwo_str:
        calc = math.floor(((charone_str - chartwo_str)/ 5))
        return calc
    elif chartwo_str > charone_str:
        calc = math.floor(((chartwo_str - charone_str)/ 5))
        return calc
    elif charone_str == chartwo_str:
        calc = math.floor(((charone_str - chartwo_str)/ 5))
        return calc

def skl_mod(charone_skl, chartwo_skl):
    if charone_skl > chartwo_skl:
        calc = math.floor(((charone_skl - chartwo_skl)/ 5))
        return calc
    elif chartwo_skl > charone_skl:
        calc = math.floor(((chartwo_skl - charone_skl)/ 5))
        return calc
    elif charone_skl == chartwo_skl:
        calc = math.floor(((charone_skl - chartwo_skl)/ 5))
        return calc

def mods():
    global strength_mod
    global skill_mod
    global counter
    strength_mod = str_mod(charone_strength, chartwo_strength)
    skill_mod = skl_mod(charone_skill, chartwo_skill)
    print "\nRound",counter
    print "-------"
    time.sleep(1)
    print "\nFor this round, the strength modifier is:",strength_mod
    time.sleep(0.20)
    print "For this round, the skill modifier is: ",skill_mod
    time.sleep(0.20)
    diceroll(charone, chartwo)
    print "\n"+str(charone)+"'s","dice roll is:",player1
    time.sleep(1)
    print "\n"+str(chartwo)+"'s","dice roll is:",player2

def diceroll(charone, chartwo):
    print "\n"+str(charone)+" will roll the 6 sided dice first!"
    time.sleep(0.5)
    global player1
    player1 = random.randint(1,6)
    delay_print("\nRolling dice!")
    global player2
    player2 = random.randint(1,6)
    time.sleep(0.5)
    print "\nNow",chartwo,"will roll the 6 sided dice!"
    time.sleep(0.5)
    delay_print("\nRolling dice!")
# problem function
def suddendeath():
    global charone_strength
    global chartwo_strength
    print "\n============"
    print "SUDDEN DEATH"
    print "============"
    time.sleep(1)
    player1 = random.randint(1,6)
    player2 = random.randint(1,6)
    print "\n"+str(charone)+" has rolled:",player1
    time.sleep(0.5)
    print "\n"+str(chartwo)+" has rolled:",player2
    if player1 == player2:
        print "\nIt's a draw!"
        suddendeath()
    if player1 > player2:
        chartwo_strength = 0
    elif player2 > player1:
        charone_strength = 0

def battle(charone_str, chartwo_str, charone_skl, chartwo_skl, str_mod, skl_mod):
    global charone_strength
    global charone_skill
    global chartwo_strength
    global chartwo_skill
    global counter
    if str_mod < 3:
        print "\nStrength modifier is too low, it will be increased by 5"
        str_mod += 5
        time.sleep(0.5)
    if skl_mod < 3:
        print "\nSkill modifier is too low, it will be increased by 5"
        skl_mod += 5
        time.sleep(0.5)
    if player1 == player2:
        print "\nThis round is a draw! No damage done"
        counter += 1
    elif player1 > player2:
        if counter in [20,40,60,80,100,120,140,160,180,200]:
            print "\nDuring this turn, a power up of +50% will be awarded"
            charone_strength = charone_strength + (charone_strength/2)
            time.sleep(0.5)
            print "50% of",str(charone)+"'s strength will be dealt as damage to",chartwo
            chartwo_strength = chartwo_strength - (charone_strength/2)
            time.sleep(0.5)
        else:
            pass
        charone_strength = charone_str + str_mod
        charone_skill = charone_skl + skl_mod
        chartwo_strength = chartwo_skl - str_mod
        chartwo_skill = chartwo_skl - skl_mod
        if charone_skill <= 0:
            charone_skill = 0
        elif chartwo_skill <= 0:
            chartwo_skill = 0
        print "-------------------------"
        print charone+" won this round"
        print "-------------------------"
        print "\n"+"Character 1:",charone
        print "Strength:",charone_strength
        print "Skill:",charone_skill
        time.sleep(1)
        print "\nCharacter 2:",chartwo
        print "Strength:",chartwo_strength
        print "Skill:",chartwo_skill
        print "-------------------"
        counter += 1
    elif player2 > player1:
        if counter in [20,40,60,80,100,120,140,160,180,200]:
            print "\nDuring this turn, a power up of +50% will be awarded"
            chartwo_strength = chartwo_strength + (chartwo_strength/2)
            time.sleep(0.5)
            print "50% of",str(chartwo)+"'s strength will be dealt as damage to",charone
            charone_strength = chartwo_strength - (charone_strength/2)
            time.sleep(0.5)
        else:
            pass
        chartwo_strength = chartwo_str + str_mod
        chartwo_skill = chartwo_skl + skl_mod
        charone_strength = charone_str - str_mod
        charone_skill = charone_skl - skl_mod
        if charone_skill <= 0:
            charone_skill = 0
        elif chartwo_skill <= 0:
            chartwo_skill = 0
        print "-------------------------"
        print chartwo+" won this round"
        print "-------------------------"
        print "Character 1:",charone
        print "Strength:",charone_strength
        print "Skill:",charone_skill
        time.sleep(1)
        print "\nCharacter 2:",chartwo
        print "Strength:",chartwo_strength
        print "Skill:",chartwo_skill
        print "-------------------"
        counter += 1

charone = raw_input("\nEnter the name of character one: ")
chartwo = raw_input("Enter the name of character two: ")
time.sleep(1.5)
print "\n",charone,"has encountered",chartwo
delay_print("\nBattle Initiated!")

charone_strength = int(raw_input("\nEnter the strength score for "+str(charone)+": "))
while charone_strength < 1 or charone_strength > 100:
    print "Please enter a number from 1-100"
    charone_strength = int(raw_input("\nEnter the strength score for "+str(charone)+": "))

charone_skill = int(raw_input("Enter the skill score for "+str(charone)+": "))
while charone_skill < 1 or charone_skill > 100:
    print "Please enter a number from 1-100"
    charone_skill = int(raw_input("\nEnter the skill score for "+str(charone)+": "))
time.sleep(1.0)

chartwo_strength = int(raw_input("\nEnter the strength score for "+str(chartwo)+": "))
while chartwo_strength < 1 or chartwo_strength > 100:
    print "Please enter a number from 1-100"
    chartwo_strength = int(raw_input("\nEnter the strength score for "+str(chartwo)+": "))

chartwo_skill = int(raw_input("Enter the skill score for "+str(chartwo)+": "))
while chartwo_skill < 1 or chartwo_skill > 100:
    print "Please enter a number from 1-100"
    chartwo_skill = int(raw_input("\nEnter the skill score for "+str(chartwo)+": "))

time.sleep(2)
print "\nCharacter 1:",charone
print "Strength:",charone_strength
print "Skill:",charone_skill
time.sleep(1)
print "\nCharacter 2:",chartwo
print "Strength:",chartwo_strength
print "Skill:",chartwo_skill
time.sleep(1)

#problem loop
while charone_strength > 0 or chartwo_strength > 0:
    if counter == 220:
        print "\nRound 220 has been reached, Sudden Death Mode active!"
        suddendeath()
    else:
        mods()
        battle(charone_strength, chartwo_strength, charone_skill, chartwo_skill, strength_mod, skill_mod)
else:
    if charone_strength <= 0:
        print "\n"+str(charone)+" has died!",chartwo,"wins!"
        time.sleep(1)
    elif chartwo_strength <= 0:
        print "\n"+str(chartwo)+" has died!",charone,"wins!"
        time.sleep(1)
    play = raw_input("Would you like to play again? y/n: ")
    if play in ["yes","y","Yes","Y"]:
        execfile("gcse.py")
    else:
        print "Goodbye! Thanks for playing!"
        exit()