Lua need help adding a chance rate to this if its possible! tfs 1.3

[fig niggy]

changing around the unrealistic dream item to make it do what i need if at all possible!
can some one show me or make me a lua with this that adds a chance rate of getting said item so i can make some more rare than others? or is there a better approach to something like this?

 

[Xikini]

-- edit -> Didn't realise it was TFS 1.3 you were after.
Guess I'll just leave both 0.4 and 1.3

1.3

local rewardItems = {
    --[{chance}] = itemid 
    --[{low, high}] -- if chance is equal to or inbetween these 2 numbers, then give item.
    
    -- example chance 1/1700
    --[{1, 1}]  = 13537, -- Bag of Apple Slices
    
    -- example chance 100/1700 aka 1/17
    --[{1, 100}]  = 13537, -- Bag of Apple Slices
    
    
    [{   1,  100}]  = 13537, -- Bag of Apple Slices
    [{ 101,  200}]  = 22609, -- Dream Warden Claw
    [{ 201,  300}]  = 2355,  -- Stuffed Bunny
    [{ 301,  400}]  = 5792,  -- Dice
    [{ 401,  500}]  = 7459,  -- Pair of Earmuffs
    [{ 501,  600}]  = 2111,  -- Snowball
    [{ 601,  700}]  = 2114,  -- Piggy Bank
    [{ 701,  800}]  = 2657,  -- Simple Dress
    [{ 801,  900}]  = 1990,  -- Present
    [{ 901, 1000}]  = 2745,  -- Blue Rose
    [{1001, 1100}]  = 2072,  -- Lute
    [{1101, 1200}]  = 22606, -- Bronze Prison Key
    [{1201, 1300}]  = 22604, -- Silver Prison Key
    [{1301, 1400}]  = 22607, -- Golden Prison Key
    [{1401, 1500}]  = 22396, -- Cluster of Solace
    [{1501, 1600}]  = 7735,  -- Spellwand
    [{1601, 1700}]  = 22605  -- Copper Prision Key
}

function onUse(player, item, fromPosition, target, toPosition, isHotkey)
    local rand = math.random(1700)
    for chance, item_id in pairs(rewardItems) do
        if chance[1] <= rand and chance[2] >= rand then
            player:addItem(item_id, 1, true)
            item:remove(1)
            player:getPosition():sendMagicEffect(CONST_ME_BUBBLES)
            return true
        end
    end
    return true
end

0.4

local rewardItems = {
    --[{chance}] = itemid
    --[{low, high}] -- if chance is equal to or inbetween these 2 numbers, then give item.
   
    -- example chance 1/1700
    --[{1, 1}]  = 13537, -- Bag of Apple Slices
   
    -- example chance 100/1700 aka 1/17
    --[{1, 100}]  = 13537, -- Bag of Apple Slices
   
   
    [{   1,  100}]  = 13537, -- Bag of Apple Slices
    [{ 101,  200}]  = 22609, -- Dream Warden Claw
    [{ 201,  300}]  = 2355,  -- Stuffed Bunny
    [{ 301,  400}]  = 5792,  -- Dice
    [{ 401,  500}]  = 7459,  -- Pair of Earmuffs
    [{ 501,  600}]  = 2111,  -- Snowball
    [{ 601,  700}]  = 2114,  -- Piggy Bank
    [{ 701,  800}]  = 2657,  -- Simple Dress
    [{ 801,  900}]  = 1990,  -- Present
    [{ 901, 1000}]  = 2745,  -- Blue Rose
    [{1001, 1100}]  = 2072,  -- Lute
    [{1101, 1200}]  = 22606, -- Bronze Prison Key
    [{1201, 1300}]  = 22604, -- Silver Prison Key
    [{1301, 1400}]  = 22607, -- Golden Prison Key
    [{1401, 1500}]  = 22396, -- Cluster of Solace
    [{1501, 1600}]  = 7735,  -- Spellwand
    [{1601, 1700}]  = 22605  -- Copper Prision Key
}

function onUse(cid, item, frompos, item2, topos)
    local rand = math.random(1700)
    for chance, item_id in pairs(rewardItems) do
        if chance[1] <= rand and chance[2] >= rand then
            doPlayerAddItem(cid, item_id, 1)
            doRemoveItem(item.uid, 1)
            doSendMagicEffect(getPlayerPosition(cid), 26)
            return true
        end
    end
    return true
end