How to Make a Bank with Interest- Difficulty 🟧 or 6.5/10

While I was creating my Tycoon Game in Gimkit, I wanted to create a bank system that allowed players to deposit 50% of their cash, but be able to withdraw it later, with an extra 1% bonus. You can do this, which is pretty surprising to me.

What you’ll need for this tutorial:

Item Granter x2
Property x3
Random Prop(Preferably “Safe”) x1
Button x1
Popup x1
Counter x1
Repeater x1
Inventory Item Manager x1

Step 1

First, place down a prop, and near a prop place a button. Make the button say something like “Open the Bank Menu” or something.

Then, wire it to a popup.

This is what your result should look like:

Step 2:

Create a call to action label that says “Store x% of your [insert currency]”, with x being any percentage and [insert currency] being any currency.

Now create a secondary call to action label that says "Withdraw your [insert currency]'.

Wire the popup to two item granters. The wires should look like this:

Step 3

Now, place down three properties.

Property 1: “Money”
Property 2: “CM”(Abbreviated for “Current Money”)
Property 3: “Seconds”

Place down an inventory item manager. Make it track whatever item you want. Now, go to blocks and pick the block “When amount of item changes…”. Place these blocks down.

Step 4

Place down a repeater and a counter. Make the repeater repeat every [insert number] seconds. Make it start when receiving “Stored”(We’ll get to that later). Anyways, after that, wire it to a counter so that when the repeater repeats increment the counter by 1. Also, make the counter reset after receiving on channel “Withdrawn”(We’ll also get to that later). It should look like this:

Step 5

Change the item granter that stores your currency so it gives whatever item you want it to give, and 0 of that item. Then, create a block that says “On wire pulse…”.

Next, create a variable named “CM” and place down these blocks.


Step 6

For the next item granter, do the same thing, except place these blocks:



In Step 5, we need to use the property named “CM” because it represents how much currency stored in the bank, and when you withdraw that currency, it doesn’t just give you 50% of your current currency.

The seconds thing in step 5 is to give interest! When the counter increments, the amount of percentage of the currency you originally had goes up, making you earn more cash! This is an incentive for a bank- Being able to make cash. Plus, if you have the maximum amount of an item, you can also store stuff.

Optional Challenge: This concept uses simple interest. If you want, show me this system, but using compound interest.

Additional Images:

The Bank Menu

5,000 Cash

First Store

Second Store

Cash Withdrawl- With interest!

Anyways, this was the longest tutorial yet. What difficulty should this tutorial be?

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0 voters



If the difficulty is 3.5/5 not a 4/5 I would replace the red square with an orange.



ok i’ll do that


nice guide!
also, how did u make the arrow thing that points to the “first dropper” (is it waypoint)


it would have to be @Pika_Pokemon (very nice guide btw)


It’s a waypoint


Interesting idea! You could also use compound interest formulas (a = p(1+r/n)^(n*t) when a is the updated value, p is the initial value, r is the interest rate (1% = 0.01), n is the number of times the interest is compounded in a given time period (usually a year, but can be changed to suit your scenario), and t is the number of time periods (years) in a given scenario) to allow for more complex calculations.

For example, $2500 being deposited in the bank for 300 seconds (compounded every minute) with an interest rate of 5% would be represented as a = 2500((1+0.05/1)^(1*5)) and would be returned as $3,190.70 once removed from the bank. Alternatively, if you don’t want to find a predetermined amount of time to reference (like 60 seconds) and round down to find that value (note that rounding down works because the 5 in my equation would become 0 and anything to the power of 0 is 1 - this ensures that you don’t accidentally multiply the starting value by 0 and lose all your money), you could use continually compounding interest to constantly update that value: a = p*(2.7183^(r*t))

Input the starting value as p, the interest rate as r, and the number of seconds as t. Our previous example would be represented as a = 2500*(2.7183^(0.05*5)), which would return a value of $3,210.06 - note that you still have to round down to find the nearest minute value (because the original equation uses t to represent years and we’re just changing it to minutes for convenience), but the outputted value is a larger number. Continuous compounding is considered to be the most favorable type of interest compounding because the interest is reinvested into the account more frequently than any other method, so if you want to maximize the amount of money that a user is getting out of the bank at any given time, you might want to consider using that method instead.

Feel free to ask if you have any questions… that was a pretty vague explanation :]


The only reason I didn’t use compound interest is because I was too lazy to make the compound interest system. Also, I like how you used e as the base


I can make an example system for you to reference if you want :p (I’m in class right now and don’t really have anything else to do)… and yes - I substituted it for 2.7183 for convenience, but that’s the way that I personally learned how to do it.


i decided not to compound interest because that’s not really the game. the game is actually just meant to be some funny lil tycoon game and I never considered adding exponential growth or decay in because my algebra skills are bad


Oh, okay… here I am, doing the math, when the point is to not do the math. Originally I was thinking of doing it for the sake of the guide, but that makes sense - good luck with your game, then!


thanks for the gl!!!


This is pretty legit stuff for a game I play with my 5th graders.

I originally, years ago, had them play Gimkit to review material.

Now, I plan on implementing coding lessons with it as well. And I guess I can now expose them to compound interest formulas.


Hey, I learned how to do basic trigonometry (so that I could make rudimentary enemy pathfinding) before I ever learned how to do it in a math class - programming and game design require a fair amount of math, and personally I think making games is a more interesting way of learning about math than typical lessons usually are. You have to explain the formula to someone either way, but if you also explain why it’s important to learn (and what the applications are), you give them a reason to make more of an effort when learning. It certainly seems more exciting than textbooks and worksheets, anyway :]


Learning math before you take it is fun cuz you get to have high marks in math and flex on everyone else. Computer Science requires math, yes, and people should definitely learn linear algebra and optimization basics before pursuing it as a full-on passion.


agreed. i take algebra 1 honors next year, but i already know plenty…


There isn’t really much hard about Algebra 1. It’s just a lot of new content like quadratic, exponential functions(compound interest too!), linear equation systems, radicals, rational functions(you might get this far), and more stats.


Speaking of that, what math courses are you taking as of now?


Next year will be precalculus, I think. I took accelerated math classes for a while so that I could take computer science classes for all four years of high school, but I’m probably going to take regular classes for a while (so next year’s class will be one year ahead of whatever it would normally be)


noice. (extra characters)