There are several ways you can do it. The most popular is probably the method Vendetta came up with. Here’s a link to his original thread Venettas save system.
This is Zombien’s Savegame file if you want to see what it looks like when it is working.
*if save_flag = "save"
*set shealth health
*set sname name
*set ssurname surname
*set sgender gender
*set sprofession profession
*set sscavenging scavenging
*set snegotiation negotiation
*set smechanical mechanical
*set sunarmed unarmed
*set smelee melee
*set sranged ranged
*set sleadership leadership
*set sstrength strength
*set sagility agility
*set sspeed speed
*set sstamina stamina
*set sintellect intellect
*set sinfluence influence
*set sempty empty
*set shandgun handgun
*set srifle rifle
*set sshotgun shotgun
*set scrossbow crossbow
*set sknife knife
*set ssword sword
*set scrowbar crowbar
*set sscrewdriver screwdriver
*set scleaver cleaver
*set sbackpack backpack
*set sfirstaid firstaid
*set storch torch
*set scandles candles
*set sbinoculars binoculars
*set sfood food
*set swater water
*set sfishingrod fishingrod
*set scigarettes cigarettes
*set srope rope
*set swallet wallet
*set sphone phone
*set sstick stick
*set sstick2 stick2
*set swrench wrench
*set sorientation orientation
*set sBob_faction Bob_faction
*set sSimon_faction Simon_faction
*set sMax_faction Max_faction
*set sJacob_faction Jacob_faction
*set sAlice_faction Alice_faction
*set sSarah_faction Sarah_faction
*set sRachel_faction Rachel_faction
*set sTaylor_faction Taylor_faction
*set sMoira_faction Moira_faction
*set smet_bob met_bob
*set smet_simon met_simon
*set smet_max met_max
*set smet_jacob met_jacob
*set smet_alice met_alice
*set smet_sarah met_sarah
*set smet_rachel met_rachel
*set smet_taylor met_taylor
*set smet_moira met_moira
*set she he
*set shis his
*set sman man
*set shim him
*set shimself himself
*set sxenon_saved xenon_saved
*set strucktry trucktry
*set spolice police
*set sisland island
*set sstore_visit store_visit
*set sstore store
*set scastle castle
*set sback_store back_store
*set scouple_bob couple_bob
*set scouple_simon couple_simon
*set scouple_max couple_max
*set scouple_jacob couple_jacob
*set scouple_alice couple_alice
*set scouple_sarah couple_sarah
*set scouple_rachel couple_rachel
*set scouple_taylor couple_taylor
*set scouple_moira couple_moira
*set ssingle single
*set slike_sarah like_sarah
*set slike_jacob like_jacob
*set slike_bob like_bob
*set slike_simon like_simon
*set slike_max like_max
*set slike_alice like_alice
*set slike_rachel like_rachel
*set slike_taylor like_taylor
*set slike_moira like_moira
*set sdead_bob dead_bob
*set sdead_simon dead_simon
*set sdead_max dead_max
*set sdead_jacob dead_jacob
*set sdead_alice dead_alice
*set sdead_sarah dead_sarah
*set sdead_rachel dead_rachel
*set sdead_taylor dead_taylor
*set sdead_moira dead_moira
*set sembrace1 embrace1
*set sembrace2 embrace2
*set splay1 play1
*set splay2 play2
*set srebel1 rebel1
*set ssr_hon sr_hon
*set ssr_vag sr_vag
*set scity1 city1
*set swoods1 woods1
*set smet_xenon met_xenon
*set sxenon_faction xenon_faction
*set smean1 mean1
*set sfriendly1 friendly1
*set sinvestigate_yes investigate_yes
*set sinvestigate_pretend investigate_pretend
*set sinvestigate_no investigate_no
*set spromise1 promise1
*set sfree1 free1
*set spsba psba
*set spba pba
*set sps ps
*set spl pl
*set sismj ismj
*set sism ism
*set sisj isj
*set simj imj
*set sis is
*set sim im
*set sij ij
*set sil il
*set ssstm sstm
*set ssst sst
*set sstm stm
*set sss ss
*set sst st
*set ssl sl
*set sabandoned abandoned
*set smet_rebels met_rebels
*set srebel_faction rebel_faction
*set stookbase tookbase
*set sworkbase workbase
*set sbuild_base build_base
*set sdays days
*set splasma_gun plasma_gun
*set spower power
*set sspacearmour spacearmour
*set smet_wally met_wally
*set swallybang wallybang
*set sbetray betray
*set sa57 a57
*set sbattlewon battlewon
*set sbeth beth
*set sfakename fakename
*set skilled_xenon killed_xenon
*set sdarkside darkside
*set smissab missab
*set ssu su
*set sju ju
*set stu tu
*set sextra extra
*set sehe ehe
*set sehis ehis
*set seman eman
*set sehim ehim
*set seboy eboy
*set sename ename
*set sesister esister
*set sx_faction x_faction
*set sr_faction r_faction
*set syear year
*set sxenonhelped xenonhelped
*set sradonhelped radonhelped
*goto saveload
*if save_flag = "restore"
*set health shealth
*set name sname
*set surname ssurname
*set gender sgender
*set profession sprofession
*set scavenging sscavenging
*set negotiation snegotiation
*set mechanical smechanical
*set unarmed sunarmed
*set melee smelee
*set ranged sranged
*set leadership sleadership
*set strength sstrength
*set agility sagility
*set speed sspeed
*set stamina sstamina
*set intellect sintellect
*set influence sinfluence
*set empty sempty
*set handgun shandgun
*set rifle srifle
*set shotgun sshotgun
*set crossbow scrossbow
*set knife sknife
*set sword ssword
*set crowbar scrowbar
*set screwdriver sscrewdriver
*set cleaver scleaver
*set backpack sbackpack
*set firstaid sfirstaid
*set torch storch
*set candles scandles
*set binoculars sbinoculars
*set food sfood
*set water swater
*set fishingrod sfishingrod
*set cigarettes scigarettes
*set rope srope
*set wallet swallet
*set phone sphone
*set stick sstick
*set stick2 sstick2
*set wrench swrench
*set orientation sorientation
*set Bob_faction Bob_faction
*set Simon_faction sSimon_faction
*set Max_faction sMax_faction
*set Jacob_faction sJacob_faction
*set Alice_faction sAlice_faction
*set Sarah_faction sSarah_faction
*set Rachel_faction sRachel_faction
*set Taylor_faction sTaylor_faction
*set Moira_faction sMoira_faction
*set met_bob met_bob
*set met_simon smet_simon
*set met_max smet_max
*set met_jacob smet_jacob
*set met_alice smet_alice
*set met_sarah smet_sarah
*set met_rachel smet_rachel
*set met_taylor smet_taylor
*set he she
*set his shis
*set man sman
*set him shim
*set himself shimself
*set xenon_saved sxenon_saved
*set trucktry strucktry
*set police spolice
*set island sisland
*set store_visit sstore_visit
*set store sstore
*set castle scastle
*set back_store sback_store
*set couple_bob scouple_bob
*set couple_simon scouple_simon
*set couple_max scouple_max
*set couple_jacob scouple_jacob
*set couple_alice scouple_alice
*set couple_sarah scouple_sarah
*set couple_rachel scouple_rachel
*set couple_taylor scouple_taylor
*set couple_moira scouple_moira
*set single ssingle
*set like_sarah slike_sarah
*set like_jacob slike_jacob
*set like_bob slike_bob
*set like_simon slike_simon
*set like_max slike_max
*set like_alice slike_alice
*set like_rachel slike_rachel
*set like_taylor slike_taylor
*set like_moira slike_moira
*set dead_bob sdead_bob
*set dead_simon sdead_simon
*set dead_max sdead_max
*set dead_jacob sdead_jacob
*set dead_alice sdead_alice
*set dead_sarah sdead_sarah
*set dead_rachel sdead_rachel
*set dead_taylor sdead_taylor
*set dead_moira sdead_moira
*set embrace1 sembrace1
*set embrace2 sembrace2
*set play1 splay1
*set play2 splay2
*set rebel1 srebel1
*set sr_hon ssr_hon
*set sr_vag ssr_vag
*set city1 scity1
*set woods1 swoods1
*set met_xenon smet_xenon
*set xenon_faction sxenon_faction
*set mean1 smean1
*set friendly1 sfriendly1
*set investigate_yes sinvestigate_yes
*set investigate_pretend sinvestigate_pretend
*set investigate_no sinvestigate_no
*set promise1 spromise1
*set free1 sfree1
*set psba spsba
*set pba spba
*set ps sps
*set pl spl
*set ismj sismj
*set ism sism
*set isj sisj
*set imj simj
*set is sis
*set im sim
*set ij sij
*set il sil
*set sstm ssstm
*set sst ssst
*set stm sstm
*set ss sss
*set st sst
*set sl ssl
*set abandoned sabandoned
*set met_rebels smet_rebels
*set rebel_faction srebel_faction
*set tookbase stookbase
*set workbase sworkbase
*set build_base sbuild_base
*set days sdays
*set plasma_gun splasma_gun
*set power spower
*set spacearmour sspacearmour
*set met_wally smet_wally
*set wallybang swallybang
*set betray sbetray
*set a57 sa57
*set battlewon sbattlewon
*set beth sbeth
*set fakename sfakename
*set killed_xenon skilled_xenon
*set darkside sdarkside
*set missab smissab
*set su ssu
*set tu stu
*set ju sju
*set extra sextra
*set ehe sehe
*set ehis sehis
*set eman seman
*set ehim sehim
*set eboy seboy
*set ename sename
*set esister sesister
*set x_faction sx_faction
*set r_faction sr_faction
*set year syear
*set xenonhelped sxenonhelped
*set radonhelped sradonhelped
*goto saveload
*label saveload
*if save_flag = "save"
*set save_flag ""
GAME SAVED!
*line_break
If your adventures prove too much and you become one of the "living impaired" you can always start again from here.
*line_break
(Unless you close the browser... then you are on your own)
*set save_msg true
*page_break Continue
*if return_to_scene = "home"
*goto_scene home
*elseif return_to_scene = "chapter1"
*goto_scene chapter1
*elseif return_to_scene = "chapter2"
*goto_scene chapter2
*elseif return_to_scene = "chapter3"
*goto_scene chapter3
*elseif return_to_scene = "chapter4"
*goto_scene chapter4
*elseif return_to_scene = "chapter5"
*goto_scene chapter5
*elseif return_to_scene = "chapter6"
*goto_scene chapter6
*else
*goto error
*elseif save_flag = "restore"
*page_break
Couldn't quite cut it huh? Well thats ok, backtrack a bit and see if you can do better.
*page_break Continue
*if return_to_scene = "home"
*goto_scene home
*elseif return_to_scene = "chapter1"
*goto_scene chapter1
*elseif return_to_scene = "chapter2"
*goto_scene chapter2
*elseif return_to_scene = "chapter3"
*goto_scene chapter3
*elseif return_to_scene = "chapter4"
*goto_scene chapter4
*elseif return_to_scene = "chapter5"
*goto_scene chapter5
*elseif return_to_scene = "chapter6"
*goto_scene chapter6
*else
*goto error
*label error
I'm sorry, but there seems to have been a problem saving or loading your game. Please take a minute to head to the choice of games website and leave a message for the author so he can fix this problem as soon as possible. Please include as much detail as possible.