Spoilers ahead:

This guide disregards gains through character creation; some traits give bonus attribute points!

Maximum in-game improvements:

• Strength (+2 permanent, +3-4 via equipment, +9 buffed)
• Perception (+2 permanent, +8 buffed)
• Endurance (+1 permanent, +7 buffed)
• Charisma (+2 permanent, +1 via equipment, +5 buffed)
• Intelligence (+3 permanent, +7 buffed)
• Agility (+1 permanent, +9 buffed)
• Luck (+4)

Notes:

• The max value for all primary stats is 10.
• All drug effects can be taken twice, and they all stack.
  • For example, taking Buffout (+2 strength) two times will give +4 strength. Taking Jet (+1 strength) two times will give +2 strength. Combined, you will get +6 strength from taking 2 Buffout and 2 Jet.
• All surgery enhancements require using a machine within a Brotherhood of Steel bunker in San Francisco. How to access the machine:

To gain access to this machine without killing anyone, complete Get the virtibird plans for the Brotherhood of Steel. (And nab the Advanced Power Armor and Blue Memory Module while doing it!) Make sure to give to the plans to the Brotherhood of Steel before the Shi, because the Shi will simply take the plans, where the Brotherhood will give you a copy!

Strength (+2 permanent, +9 buffed)

+1 via surgery, +1 via perk, +3-4 via armor (while equipped), +1-6 via drugs (temporary)

A strength above 7 is usually unnecessary during character creation.

1. (+3-4 while equipped) Power armor:

   • T-51b Power Armor (+3)
   • Hardened Power Armor (+3)
   • Advanced Power Armor (+4)
   • Advanced Power Armor Mk II (+4)

2. (+1) Red Memory Module surgery. Where to find it:

   You can find this chip in the vault within Vault City. It is behind one of the doors which is jammed on the second floor. You can get to it with a strength of 7 and a crowbar (use the crowbar on the door) (consider using Buffout if your strength is too low). Use the chip with the computer in the Brotherhood of Steel bunker in San Francisco.

3. (+1) Gain Strength perk

4. (+2 temporary) (+4 if taken twice) Buffout drug. Tip:

   This can be useful in several situations, like getting to the memory chip in Vault City, or defeating the super mutant in Broken Hills at an arm wrestling challenge.

5. (+1 temporary) (+2 if taken twice) Jet drug

Perception (+2 permanent, +8 buffed)

+1 via surgery, +1 via perk, +1-6 via drugs (temporary)

1. (+1) Green Memory Module surgery. Where to find it:

   This chip can be found in the Military Base East of San Francisco and far West of NCR. It is on the third floor (you will need to repair the broken generator on the first floor) in a locker which is easily accessible without encountering any super mutants. Use the chip with the computer in the Brotherhood of Steel bunker in San Francisco.

2. (+1) Gain Perception perk

3. (+2 temporary) (+4 if taken twice) Mentats drug

4. (+1 temporary) (+2 if taken twice) Jet drug

Endurance (+1 permanent, +7 buffed)

+1 via perk, +3-6 via drugs (temporary)

1. (+1) Gain Endurance perk

2. (+3 temporary) (+6 if taken twice) Buffout drug

Charisma (+2 permanent, +5 buffed)

+1 via surgery, +1 via perk, +1 via item (while equipped), +1-2 via drugs (temporary)

1. (+1) Blue Memory Module surgery. Where to find it:

   You can find this in Navarro, in the underground section, in a locker in the North West corner of the map. You need to be told about Navarro's existence before you can go there. Both Matt and Ron will give you a quest to go there. Use the chip on the computer in the Brotherhood of Steel bunker in San Francisco.

2. (+1) Gain Charisma perk

3. (+1 while equipped) Mirrored Shades when carried in an active item slot (the punch or kick slot). Where to find them:

   You can find these by digging up a grave in Golgotha, or by killing Mason who is a guard on the second floor of the Salvatores bar in New Reno. You can find Golgotha by either talking to Jules for long enough (you see him when you first enter New Reno), from Myron when you tell him to 'Wait here.' after he has joined your squad (he will offer you a favor, let him tell you about it, you can promptly ditch him afterwords), or by completing the first mission given to you by the Salvatores (where Mason is).

4. (+1 temporary) (+2 if taken twice) Mentats drug

Intelligence (+2-3 permanent, +7 buffed)

+1 via surgery, +1 via story element, +1 via perk, +2-4 via drugs (temporary)

1. (+1) Yellow Memory Module surgery. Where to find it:

   The module can be found in the Sierra Army Depot which can be found by accepting the second quest from Orville Wright; 'Find a way into the Sierra Army Base'. You never have to actually complete this quest, it is just useful to get it so that you know where the base is. You must get this quest before becoming a made man with any other faction in New Reno, otherwise you will never get into the Sierra Army Depot. Use the chip on the computer in the Brotherhood of Steel bunker in San Francisco.

2. (+1) Hubologist zeta scan. How to get it:

   In the Hubologist base in San Francisco. It can increase your intelligence by +1 and luck by +1. But, it can also simply decrease your luck by -1. So you may want to save first. Just let the 'celebrities who are not at all based on actual celebrities' give their speech (North end of the Hubologist compound which is found in the North East corner of San Francisco) and then talk to them about joining. Taking this scan will prevent you from taking the zeta scan in NCR (+2 luck).

3. (+1) Gain Intelligence perk

4. (+2 temporary) (+4 if taken twice) Mentats drug

Agility (+1 permanent, +9 buffed)

+1 via perk, +2-9 via drugs (temporary)

Every two points of agility give you 1 action point, so putting this to 10 (9 if you plan on eventually getting the perk) at the beginning of the game is a good way to go because having lots of action points is very useful. However, action points can also be gained through some other perks.

1. (+1) Gain Agility perk

2. (+2 temporary) (+4 if taken twice) Buffout drug

3. (+3 temporary) (+6 if taken twice) Psycho drug

Luck (+3-4 permanent)

+1 via perk, +1-2 via story elements, +1 via game encounter

1. (+1) Gain Luck perk

2. (+1-2) The Hubologist zeta scan. How to get it:

   In NCR. It can increase your luck by +2. But, it can also simply decrease your luck by -1. You may want to save before taking it. You can find this Hubologist alone in a building in the center of NCR wearing purple robes. Taking this will prevent you from taking the zeta scan in San Francisco (+1 intelligence, +1 luck - see Intelligence zeta scan).

3. (+1) The Pariah dog. How to get it:

   This dog can only be found in a random encounter. It can increase your luck by +1 if you kill it before it joins your party. If you fail a luck roll, he joins your party and you suffer a loss of -1 luck until you kill him. If you manage to kill him.

Bonus: in-game cheat for maxing all stats

There is a way to max all of your stats once you've finished the main quest: (though it is basically a cheat mode)

Upon completing the game (or at least the main quest), you can travel to New Reno and visit Father Tully. So long as he is conscious (he is often passed out; you can just rest a little and see if he wakes up), you can talk to him and get a little reward: The Fallout 2 Hintbook. "Well, THIS would have been good to have at the beginning of the goddamn game." Using this book will boost all of your stats and skills to their maximum values. And give you a boatload of experience. You can use the book over and over.

Perhaps the best walkthrough for Fallout 2 I have found, which includes all of these details and countless more: https://lemmings19.github.io/fallout-2-walkthrough/

(PE 9, IN 9 and LK 9)

| It is possible to pass and become a citizen right away, but you need to boost the right stats (PE 9, IN 9 and LK 9). The physical examination will disqualify you if you've grown extra toes in the Toxic Caves and didn't have them removed yet. You get 1000 xp if you pass the test.

Source: http://user.tninet.se/~jyg699a/fallout2.html