DAMAGE:

Built in +70 attack damage (W) Drunken Rage

UTILITY:

Built in "Exhaust" every 6 seconds (Q) Barrel Roll + (E) Body Slam
2 escapes (E) Body Slam + (R) Explosive Cask
1 initiate (E) Body Slam

SUSTAIN:

Mana from (W) Drunken Rage
Health from Passive Happy Hour

ITEMS:

Morellonomicon (reduce healing and regeneration)

SUMMONER SPELLS:

Run-down overextended enemies and escape with Ghost
Escape and chase with Flash (even over walls)


Most important Gragas rule:

ALWAYS have (E) Drunken Rage going, at all times.

1v1 combo:

Blackfire Torch on enemy
(E) Body Slam to damage and slow them
(Q) Barrel Roll to damage and debuff them
Auto Attack (to proc Lichbane)
As they begin to run away, (R) Explosive Cask on the far side of the enemy to push them back into you.
(E) Body Slam to damage and slow them
Auto Attack (to proc Lichbane)

If the fight is very close, use Wooglets Witchcap to stay alive long enough to use another ability.
If the fight is going badly, use Barrel Roll to escape.

Note: If the enemy is wearing Banshee's Veil don't use Blackfire Torch until you have popped the shield with Body Slam.

Team-fight combo:

Q Barrel Roll into enemy team to reduce enemy damage

Look for an opportunity for R Explosive Cask to displace enemy team by hitting the center of their group. (Make sure your team quickly attacks the same person). It is best to push enemy AD or AP champs towards your team while pushing tanks away. NOTE: Be careful that you do not give the other team a free initiate by pushing enemy Tanks into your squishy teammates.

Once an enemy gets pushed to you, perform the 1v1 combo (listed above) on them.

Gragas is one of the best farmers, but he has a slow start.

Gragas BuiltTester

Most people recommend starting with (Q) [[Barrel Roll], but I have a different approach.

I always start with Body Slam because it has a faster cooldown and provides utility (slow, initiate, escape).