Text-based adventure RPG inventory code
Some considerations on your current code:


Don't use == True. You either want to check the truth value of the object, in which case simply drop the == True, or you want to check for identity, in which case you should use is True(even though it's really rare to see is True/False. You usually check for is None).
Instead of lti == "y" or lti == "Y" or ... you can simply convert lti to lowercase and check for y. Something like lti.lower()[:1] == "y". This will include also things like yabbadu. An other option is to use in: lti.lower() in {"y", "yes"} accepts y and yes in any case(so also yEs is accepted.
You should follow the PEP8 when writing. It's the standard coding-style for python. Using it will allow all python programmers to read your code more easily. To follow this style you should use lower_case_with_underscore for functions/variables, FullCamelCase for classes.
Regarding the full code from pastebin: it is not well organized. Things like equipping an armor should be managed by a function or by some class and they shouldn't depend on the armor kind. It's probably a good example where using classes make sense. You should have an Armor class that provides the basic implementation of an armor and the various subclasses TunicArmor etc. that provide different armor points etc. Note that inheritance is not the only way to do it.


In the end the code would look like:

leather_tunic_item = False
if leather_tunic_item and not item_slot_armor_chest:
    item_slot_armor_chest = True
    chest_armor_value = 2
    print("The leather tunic is now equipped")
elif leather_tunic_item:  #no need: and item_slot_armor_chest.
    print("Your armor value is currently: ", total_armor_value, "Equipping a Leather Tunic will make this value: ", total_armor_value - chest_armor_value + 2)
    print("Would you still like to equip this item? (Yes or No)")
    lti = input("")
    if lti.lower() in {"y", "yes"}:
        item_slot_armor_chest = True
        chest_armor_value = 2
        print("Your armor value is now ", total_armor_value)
    else:
        print("This Leather Tunic will be discarded.")
        leather_tunic_item = False




A sample implementation of what I meant in the last point might be this:

class ArmorPiece:
    def __init__(self, name, points):
        self.name = name
        self.points = points


class NullPiece:
    """An armor piece that is used to represent a missing armor piece."""
    def __init__(self):
        super(NullPiece, self).__init__("", 0)


class Armor:
    def __init__(self, head=None, chest=None, legs=None):
        self.head = head if head is not None else NullPiece()
        self.chest = chest if chest is not None else NullPiece()
        self.legs = legs if legs is not None else NullPiece()

    def defense_points(self):
        return self.head.points + self.chest.points + self.legs.points


class Tunic(ArmorPiece):
    def __init__(self):
        super(Tunic, self).__init__("tunic", 2)


After this, if you want to replace the chest piece you could do:

def change_chest(armor, new_chest):
    if isinstance(armor.chest, NullPiece):
        # The player is not wearing a chest armor piece
        armor.chest = new_chest
        print("The {.name} is now equipped.".format(new_chest))
    else:
        # The player is wearing something else.
        print("Your armor value is currently: ", armor.defense_points(), "Equipping a {.name} will make this value: ".format(new_chest), armor.defense_points() - armor.chest.points + new_chest.points)
        print("Would you still like to equip this item? (Yes or No)")
        lti = input("")
        if lti.lower() in {"y", "yes"}:
            armor.chest = new_chest
            print("Your armor value is now: ", armor.defense_points())
        else:
            print("This {.name} will be discarded".format(new_chest))


You could make this function a method of Armor if you want, even though I like to separate the logic of the program from the input/output code. Your code will be more flexible.

Note that in the formatting strings the {.name} parts are replaced with the attribute name of the object passed to format. Doing "{.name}".format(new_chest) is the same as "{}".format(new_chest.name).

You should probably read a bit of the documentation about string formatting.



If you are not comfortable with classes you can simplify the code using some dictionaries. something like:

armor = {
    "head": {"name": "", "points": 0},
    "chest": {"name": "", "points": 0},
    "legs": {"name": "", "points": 0},
}

def defense_points(armor):
    return sum(value["points"] for key, value in armor.items())


To change the head armor simply do:

armor["head"] = {"name": "tunic", "points": 2}


The code to handle this would be pretty similar to the above, but replacing attribute access with item access(e.g. new_chest.name -&gt; new_chest["name"]).