Multiple attack question

[UmpteenthDoctor]

Ok so my friend who is playing the Leprechaun character is taking the Two Weapon Fighting feat to use a Quarterstaff in combat.

He also wants to take Power Attack, Cleave, and Greater Cleave.

However this says that Cleave (Make an additional attack if the first one hits) and with Greater Cleave (Make an additional attack after each attack hits.)

Now combined with TWF. Does this mean with Cleave he could attack a total of 4 times as long as his first two strikes hit if there are like 4 people there?

If you strike target a with side A of the Quarter staff with the first additional strike, and then hit target a with side b and then both side a and b hit target b would this work?

He is suggesting he can hit two foes a total of four times with this combo at +5 BAB not when he gets secondary attacks.

[Eldaran]

So, I assume this is Pathfinder, based on the way you described Cleave.

The answer is no, Cleave and Great Cleave let you make one attack as a standard action, and hit additional targets with one attack if you hit. Two weapon fighting only works when you take a full attack action (http://www.d20pfsrd.com/gamemastering/combat#TOC-Full-Attack). Since Cleave is a standard action, you can't full attack with it, so no TWF.

[cakellene]

Pathfinder version of Cleave doesn't require a killing blow?

[UmpteenthDoctor]

Cleave) [As a standard action, you can make a single attack at your full base attack bonus against a foe within reach. If you hit, you deal damage normally and can make an additional attack (using your full base attack bonus) against a foe that is adjacent to the first and also within reach. You can only make one additional attack per round with this feat. When you use this feat, you take a –2 penalty to your Armor Class until your next turn.]

Ah so he could not do both, thats good to know. How does the Two Weapon Fighting work with Additional attacks via BAB

[UmpteenthDoctor]

Do the Cleave abilities stack or cancel each other out?

[Lilapop]

Both in 3.5 and in Pathfinder, the only thing Great Cleave does is removing the 1/round restriction.
If you execute a full attack action with two weapons, you get one extra attack on your highest base attack bonus, on top of your normal BAB attack progression. The ITWF/GTWF/Superior TWF (that one doesn't exist in 3.5)/Perfect TWF line give you another attack every time you get one from increased BAB as well.
I may suffer through the formatting nightmare and provide a table that shows a detailed 16-level-build with BAB, feats and adjusted attack routine over the course of the day.