Fallout 2 skills Skill advancement . Each skill has its own skill level , which is expressed as a percentage . Skill levels can be increased by allocating skill points earned from gaining levels . Skills can also be improved by reading specific books or completing quests within the game . Raising a skill one percentage point costs one skill point . If the player character has a specifically tagged skill , one skill point will raise the corresponding skill by two percentage points . When purchasing skills , if the skill type is tagged , two skill % ( at 1 - 100 % ) are given for each skill point spent . There are no half skill points for a cost of one . Similarly , when buying skills at cost two or higher , two or more skill points must still be purchased at once , for a cost of two , or three for three , etc . ( E . g . if a skill is at 101 % , and tagged , the next purchase must be of two skill , taking the skill to 103 % , for a cost of two skill points . ) To raise a skill one percentage point ( or two if it is tagged ) when its current percentage value is between or including : Note that if the second of the two skill points bought for a tagged skill ends up above the transition between two costs , the cost is the lower one . For example , if a skill is at 100 % and tagged , spending one skill point takes the skill to 102 % for the cost of one skill point . Skill points can be left unspent and will remain , to be spent later . This could conceivably be useful in the event of a hurdle in the game of unknown type that would prevent further progress , e . g . a locked door . Any unspent skill points in excess of 99 are lost . Perks can be left unspent and saved until later . When the perk option opens simply select cancel and it will close . The perk window will keep reopening each time one enters the character screen but each time it can be closed again with cancel . However , one cannot stack perks ; if they have avoided selecting a perk and gain another one , the first perk will be lost . Effect of stats on skills . SPECIAL stats ( Strength , Perception , etc . ) modify skills with a considerable bonus . The game keeps track of this bonus throughout the game , in real time . Any changes to stats , ( e . g . chem effects , aftereffects , and addiction effects , the Hubologist zeta scans , Gain ( statistic ) perk , red memory module enhancement , mirrored shades equipped , ear bitten off by the Masticator etc . ) during the game add to or subtract from this modifier . Maximizing skill point gain / cost ratio . Reducing the base stat modifier of skills with chem effects , and / or by changing the difficulty to hard , can reduce the cost of skill points if it lowers the skill below a skill cost threshold . For example , Science can be raised to 135 % for only one skill point per % by lowering Intelligence to zero with Mentats ' aftereffects or Psycho effects ( there is a limit of two chems without saving and reloading , but that will doubtlessly be necessary in any case to avoid addiction ) , and raising the difficulty to " hard " before spending . It can be raised a further 20 % if needed , afterwards , by setting the difficulty to " easy " ( same goes for reading books ) . This also works for higher tiers of skill point cost . Note , however , a player buying the higher tiers is doubtless in late game or finished with the game story , and may prefer to just wait for or look for the Vault City designer notes after finishing the Enclave Oil Rig . List of skills . Note : The Fallout 2 Hintbook increases all skills to 300 % . To avoid cluttering the table , it is not listed for each individual skill .