Fallout, Fallout 2 and Fallout Tactics
The amount of skill points received on each level up is primarily dependent on one's Intelligence. Every level of experience will give the player character skill points. It can be further modified by certain traits or perks, such as the Skilled and Gifted traits, as well as the Educated perk.
Intelligence is the primary modifier for the number of skill points earned. The Educated perk can be taken for three additional skill points per level, for a total of 23 at maximum Intelligence. Tag skills no longer increase twice as fast, instead affecting a 15 point increase in the tagged skill. This means that a total of 658 available skill points assuming Intelligence is set to 10 at the start with Broken Steel. Through the use of skill books, it is possible to achieve 100 in every skill.
Fallout: New Vegas
In Fallout: New Vegas, the number of innate skill points remains the same at 10, but the Intelligence bonus is now halved. If Intelligence is set to an odd number, the half points will be stored and added to every other level; i.e. an Intelligence of 9 would result in skill point allowances of 14 and 15 every other level.
Tag skills function the same as before. The Educated perk now only adds two points instead of three, meaning a maximum of 17 points per level (after level 4). 30 is the maximum possible level initially, the same as Fallout 3 with Broken Steel installed. Each add-on increases the level cap by five, resulting in a final level cap of 50 with Lonesome Road.
All skill-enhancing perks have been removed or modified in such a way that they no longer increase the base value of a skill. Only Tag! provides a direct increase. Intense Training can increase skill points indirectly, as can implants which are functionally identical, but not to any significant degree. In addition, the number of skill books has been reduced, now averaging four per skill, though they are now worth four points with Comprehension instead of 2 as in Fallout 3.
Without the add-ons there is no combination of perk, SPECIAL, and skill point allocation that will allow for 100 points in every skill. With the add-ons installed, one can max every skill with an Intelligence of 4, Educated, Comprehension, and every skill book.
Fallout: The Roleplaying Game
When creating a character, the character gains their skill points after having chosen their tag skills. The amount of skill points they receive on their first level is dictated by the equation above. Every subsequent level after the first gains one additional skill point per level.
Skills can only go up 6 ranks in each skill.