V1.0.0.143:

•  Counter Strike's dodge component now works properly against Shen.

V1.0.0.140b:

•  Empower: damage reduced at later ranks to 40/75/110/145/180 from 40/85/130/175/220.

V1.0.0.139:

• fixed a bug where  Counter Strike was stunning through spell shields.

V1.0.0.138:

•  Relentless Assault (Passive): now stacks even if Jax's attack misses or is dodged.

V1.0.0.136:

• Health per level increased to 98 from 88.
•  Counter Strike: Area of effect radius increased to 375 from 350.
•  Grandmaster's Might: New Active
  • Jax gains 25/35/45 (+30% of bonus attack damage) armor and 25/35/45 (+20% of ability power) magic resist for 8 seconds.
  • 100 mana cost.
  • 80 second cooldown.

V1.0.0.135:

• Fixed a bug where  Grandmaster's Might passive attack canceled if the buff ran out during the attack animation.

V1.0.0.133:

• Mana regen per level increased to 0.7 per 5 seconds from 0.45.
• Fixed a bug where  Empower's cooldown was higher than stated at earlier ranks.
•  Counter Strike:
  • Dodge duration increased to 2 seconds from 1.5.
  • Now additionally reduces the damage from area of effect abilities by 25% for the duration.
  • It can now be activated again after 1 second to end the effect early.
  • Damage changed to 50/75/100/125/150 (+0.5 bonus attack damage) from 40/70/100/130/160 (+0.8 bonus attack damage).
  • Now deals 20% increased damage for each attack dodged (up to a maximum of 100% increased damage) instead of 10/15/20/25/30 bonus damage per dodge.
  • Cooldown reduced to 18/16/14/12/10 seconds from 22/20/18/16/14.
•  Grandmaster's Might: duration increased to 8 seconds from 6.

V1.0.0.132: Remake

• Stats:
  • Base health increased to 551 from 506.
  • Health per level increased to 88 from 83.
  • Armor per level increased to 3.5 from 3.2.
  • Added an animation to Jax's joke.
•  Relentless Assault – Passive: (Remade)
  • Every time Jax attacks an enemy he gains 4-14% increased attack speed (stacks up to 6 times).
•  Leap Strike:
  • Cooldown changed to 10/9/8/7/6 seconds from 13/11/9/7/5.
  • Damage changed to 70/110/150/190/230 (+1.0 bonus attack damage) (0.6 ability power) from 20/45/70/95/120 (+1.0 total attack damage) (0.7 ability power).
•  Empower:
  • Cooldown reduced to 7/6/5/4/3 from 9/8/7/6/5.
  • Damage changed to 40/85/130/175/220 from 60/95/130/165/200.
  • Ability power ratio increased to 0.6 from 0.4.
  • Mana cost increased to 30 from 20.
•  Counter Strike: (Remade)
  • Jax dodges all incoming basic attacks for 1.5 seconds. At the end of the effect, Jax deals 40/70/100/130/160 (+0.8 bonus attack damage) physical damage and stuns nearby enemies for 1 second. This spell deals an additional 10/15/20/25/30 damage for each attack dodged.
•  Grandmaster's Might: (Remade)
  • Passive: Every third consecutive attack deals an additional 100/160/220 (+0.7 ability power) magic damage.
  • Active: Jax gains ability power equal to 25/45/65 (+ 20% of his ability power) and attack damage equal to 25/45/65 (+20% of his bonus attack damage) for 6 seconds.

V1.0.0.124:

•  Leap Strike: base damage reduced to 20/45/70/95/120 from 35/60/85/110/135.
•  Empower:
  • Base damage reduced to 60/95/130/165/200 from 75/110/135/180/215.
  • It now breaks spell shields.

V1.0.0.123:

• Jax will now attempt to attack the target after  Leap Strike if it is an enemy champion.
• Fixed a bug where Jax's attacks could not be dodged.

V1.0.0.122:

•  Leap Strike:
  • Base damage reduced to 35/60/85/110/135 from 50/75/100/125/150.
  • Attack damage scaling increased to 100% from 70%.

V1.0.0.121:

•  Leap Strike can now target wards again, but will now reveal wards for two seconds when used in this manner.

V1.0.0.120:

•  Leap Strike: attack damage scaling reduced to 70% from 100%.
• Jax is no longer able to  Leap Strike onto wards.

V1.0.0.118:

•  Leap Strike no longer locks Jax, allowing him to cast spells while leaping.

V1.0.0.114:

•  Leap Strike now prefers to target enemies over allies when your cursor overlaps both.

V1.0.0.111:

• Updated tooltips

V1.0.0.110:

• Fixed a bug where in some instances Jax would lose health while leveling.

V1.0.0.109:

•  Leap Strike: cooldown reduced to 13/11/9/7/5 from 17/14/11/8/5.
•  Counter Strike now shows a brighter particle when Jax has recently dodged an attack and Counter Strike is ready.

V1.0.0.104:

•  Empower now properly procs Rylai's Crystal Scepter.

V1.0.0.103:

• Recommended items updated.
•  Equipment Mastery: tooltip updated to show health gained from each source dynamically.
•  Leap Strike:
  • Ability power ratio reduced to 0.7 from 0.8.
  • Cast time reduced by 20%.
  • Travel speed increased by 20%.
•  Empower:
  • Base damage increased to 75/110/145/180/215 from 40/60/80/100/120.
  • Ability power and attack damage ratios increased to 0.4 from 0.2.
  • Cooldown increased to 9/8/7/6/5 from 5 at all ranks.
  • Mana cost reduced to 20 from 35.
  • Tooltip corrected to accurately state it deals magic damage.
  • Fixed bugs where  Empower incorrectly did less damage when used at the same time as  Leap Strike or each third  Relentless Assault strike.
  • Now only deals damage to a single target rather than to an area of effect.
  • Now resets Jax’s autoattack timer when cast.
•  Counter Strike: base damage increased to 80/110/140/170/200 from 80/100/120/140/160.
•  Relentless Assault:
  • Now has an active: Grants 20/35/50 + Jax's dodge percent in bonus magic resistance for 5/6.5/8 seconds upon activation.
  • Costs 80 mana.
  • Cooldown of 60 seconds.
  • Buff icon now dynamically shows the number of  Relentless Assault stacks which Jax is benefitting from.
  • Tooltip correctly indicates that Jax gains up to 10 stacks of  Relentless Assault.

V1.0.0.101:

•  Counter Strike now has a buff that shows the duration of the effect.

V1.0.0.94(b):

• Stats:
  • Health per level reduced to 83 from 86.
  • Base movement speed reduced to 325 from 330.

V1.0.0.94:

•  Empower: cooldown changed to 5 seconds at all ranks from 7/6/5/4/3 seconds.

V1.0.0.87:

• Fixed a bug where Jax was being healed when he received bonus damage (from Guinsoo's Rageblade,  Eye Of The Storm, etc.).
• Fixed a bug where Jax could target himself with  Leap Strike.

V1.0.0.83:

• Base armor per level reduced to 3.2 from 4.
• Fixed a minor tooltip typo with  Empower.
•  Leap Strike is no longer castable while immobilized.
•  Equipment Mastery: health gained from attack damage reduced to 3 from 4.

V1.0.0.82:

•  Leap Strike: ability power ratio reduced to 0.8 from 1.0.
•  Counter Strike: ability power ratio reduced to 0.6 from 0.8.
•  Relentless Assault: ability power ratio reduced to 0.7 from 1.0.

V1.0.0.81:

• New "Selection" quote in PVP.net.

V1.0.0.79:

•  Equipment Mastery: health bonus reduced to 4 health per damage and 2 health per ability power.
•  Empower:
  • Base damage reduced to 40/60/80/100/120 from 45/65/85/105/125.
  • It now gains 20% of attack damage AND ability power as bonus damage.

V1.0.0.75:

• Stats:
  • Base mana increased to 235 from 215.
  • Mana per level increased to 35 from 30.
• New  Equipment Mastery (Innate): Jax's prowess with weapons and armor increase his fortitude as he gains equipment.
  • Jax gains 5 health per point of attack damage received from items.
  • Jax gains 3 health per point of ability power received from items.
•  Empower Remake:
  • Jax instantly charges his weapon with energy, causing him to deal 45/65/85/105/125 damage to all enemies nearby on his next attack.
  • As there is no longer a charge-up time, cooldown increased to 7/6/5/4/3 from 1 second at all ranks.
  • Changed mana cost to 35 at all ranks from 40/35/30/25/20.
•  Leap Strike can now target allies.

V1.0.0.72:

• Fixed an issue with Jax's  Leap Strike that was causing the damage to fail in some cases when interacting with targets in brush.

V1.0.0.63:

• Improved  Leap Strike's responsiveness; you can now move much sooner after striking (but not attack).

V1.0.0.61:

• Ability keys rearranged:  Leap Strike is now Q,  Empower is now W.
•  Leap Strike cooldown reduced to 17/14/11/8./5 from 21/17/13/9/5.
•  Empower:
  • Cleave increased to 60% from 50%.
  • Duration to power up reduced to 3 from 4.
  • Updated damage per second values to 25/35/45/55/65 from 20/25/30/35/40.

V0.9.22.16:

•  Counter Strike:
  • Ability power ratio reduced to 0.8 from 1.
  • Dodge reduced to 10/12/14/16/18% from 10/12.5/15/17.5/20%.
  • Cooldown increased to 4.5 from 4.
•  Relentless Assault: attack speed per level reduced to 6/10/14% from 8/12/16%.
•  Empower:
  • Can no longer crit.
  • Fixed an issue causing it to not proc.

V0.9.22.15:

•  Leap Strike:
  • Bonus damage increased to 50/75/100/125/150 from 30/60/90/120/150.
  • Now gives Jax a slight speed boost upon landing.
•  Counter Strike: dodge increased to 10/12.5/15/17.5/20% from 8/11/14/17/20%.
•  Relentless Assault:
  • Damage reduced to 140/170/210.
  • Reduced hits to proc to 3 from 4.
  • Can now be held across targets for up to 2.5 seconds.

V0.9.22.7:

• Movement speed increased to 325 from 315.

V0.8.22.115:

• Stats:
  • Base armor increased to 22 from 18.
  • Health per level increased to 86 from 78.
•  Counter Strike:
  • Cooldown reduced to 4 from 5 sec.
  • Duration of dodge proc increased to 7 from 4.

July 10, 2009 Patch:

•  Leap Strike: no longer causes double hits.
•  Relentless Assault: fixed a bug with this skill interacting with Neutral Minions.
•  Empower: now grows its damage on a per level basis instead of cleave percent.

June 12, 2009 Patch:

•  Counter Strike: ability power ratio increased to 1 from 0.5.
•  Relentless Assault: now properly shows that it has an ability power ratio of 1.

May 15, 2009 Patch:

•  Weapon Mastery: bonus damage modified to 15% from 10/15/20/25%.
•  Empower: no longer triggers item effects like Sheen, Lich Bane, and Tear of the Goddess (since its cooldown > 1 sec).

April 11, 2009 Patch:

•  Counter Strike:
  • Dodge chance reduced to 8/11/14/17/20% from 8/12/16/20/24%.
  • Mana Cost increased to 60 from 50.
•  Leap Strike:
  • Mana Cost increased to 65 from 50.
  • Cooldown increased to 22/18/14/10/6 from 21/17/13/9/5.
•  Relentless Assault:
  • No longer gives Jax additional Haste upon striking buildings.
  • Changed to Passive from Active.
  • Damage reduced to 150/200/250 from 150/225/300.
•  Empower:
  • Empower damage can no longer crit.
  • Bug fix: it no longer lasts longer than it should.

Alpha Week 7:

•  Counter Strike now has a particle effect.
• Fixed tooltip errors.
• Removed excess Dodge messages.
• Fixed a bug where Jax's Death's Caress' cooldown was not 20 as intended.