SOLID STATE PRESS
← Back to catalog
Smart Contracts: How They Work cover
Coming soon
Coming soon to Amazon
This title is in our publishing queue.
Browse available titles
Cryptocurrency & Blockchain

Smart Contracts: How They Work

Solidity, the EVM, and the Gas That Powers Every Transaction — A TLDR Primer

You keep hearing about smart contracts, DeFi, and NFTs — but every explanation either drowns you in jargon or skips the parts that actually matter. This guide cuts straight to the mechanics.

**Smart Contracts: How They Work** is a focused, plain-language primer on what smart contracts really are, how they run on the Ethereum Virtual Machine, and why they sometimes fail spectacularly. Written for high school and early college students, it assumes no prior coding experience and no background in finance or cryptography — just curiosity and a willingness to follow an idea step by step.

You will learn how the EVM executes bytecode across thousands of nodes simultaneously, why every operation costs gas paid in ETH, and how to read a basic Solidity contract without getting lost. You will trace a real transaction from the moment a user clicks "confirm" in a wallet all the way to a permanent state change on-chain. And you will see exactly how classic exploits — reentrancy attacks, integer overflows, oracle manipulation — broke real protocols and drained real money.

This is not a comprehensive Solidity textbook. It is a tight orientation: the kind of ethereum blockchain coding explained simply that lets you walk into a computer science class, a job interview, or a conversation about DeFi and actually know what people are talking about. The final section surveys where smart contracts have delivered genuine value versus where the promises still outrun the reality.

If you want to understand how blockchain technology actually executes code — not just that it does — start here.

What you'll learn
  • Explain what a smart contract is and how it differs from a traditional legal contract
  • Describe how the Ethereum Virtual Machine executes contract code and why gas exists
  • Read basic Solidity syntax: state variables, functions, modifiers, and events
  • Trace the lifecycle of a transaction from wallet signature to on-chain state change
  • Identify common vulnerabilities like reentrancy and integer overflow, and how they are mitigated
  • Recognize real-world smart contract applications including tokens, DeFi, and NFTs
What's inside
  1. 1. What a Smart Contract Actually Is
    Defines a smart contract as code stored on a blockchain that runs deterministically, contrasting it with legal contracts and ordinary software.
  2. 2. The EVM, Gas, and How Code Runs On-Chain
    Explains how the Ethereum Virtual Machine executes bytecode across thousands of nodes and why every operation costs gas paid in ETH.
  3. 3. Writing a Contract in Solidity
    Walks through the structure of a basic Solidity contract — state variables, functions, modifiers, events — using a simple token as the running example.
  4. 4. The Lifecycle of a Transaction
    Traces what happens from the moment a user clicks 'confirm' in a wallet to the contract's state being permanently updated on-chain.
  5. 5. How Smart Contracts Break: Bugs, Exploits, and Audits
    Surveys the most common smart contract vulnerabilities — reentrancy, overflow, oracle manipulation — using real historical hacks as case studies.
  6. 6. What Smart Contracts Are Actually Used For
    Surveys real applications — ERC-20 tokens, DeFi lending, NFTs, DAOs — and where smart contracts have genuinely succeeded versus where they remain hype.
Published by Solid State Press
Smart Contracts: How They Work cover
TLDR STUDY GUIDES

Smart Contracts: How They Work

Solidity, the EVM, and the Gas That Powers Every Transaction — A TLDR Primer
Solid State Press

Smart Contracts: How They Work

Solidity, the EVM, and the Gas That Powers Every Transaction — A TLDR Primer

Copyright © 2026 Solid State Press.

Published by Solid State Press.

All rights reserved. No part of this book may be reproduced or transmitted in any form without prior written permission, except for brief quotations in critical reviews and educational use.

Part of the TLDR Study Guides series.

Contents

  1. 1 What a Smart Contract Actually Is
  2. 2 The EVM, Gas, and How Code Runs On-Chain
  3. 3 Writing a Contract in Solidity
  4. 4 The Lifecycle of a Transaction
  5. 5 How Smart Contracts Break: Bugs, Exploits, and Audits
  6. 6 What Smart Contracts Are Actually Used For
Chapter 1

What a Smart Contract Actually Is

Imagine you and a friend make a bet: if it rains tomorrow, she pays you $10; if it doesn't, you pay her $10. You shake on it. The problem is that the deal only works if both of you are honest and actually hand over the money. You are trusting each other. Most agreements in the world work this way — they depend on people, institutions, or courts to enforce them.

A smart contract removes that dependency. It is a program stored directly on a blockchain that automatically executes the terms of an agreement when specific conditions are met — no middleman, no handshake, no trust required.

Blockchain here means a shared database that thousands of computers around the world maintain simultaneously, where every entry is permanent and publicly visible. Because the program lives on this shared database, no single person controls it. The code runs the same way, every time, for everyone.

Where the Idea Comes From

The term was coined by computer scientist and legal theorist Nick Szabo in 1994 — years before Bitcoin existed. Szabo's insight was that many contractual terms could be embedded in software and hardware, making breach of contract expensive or impossible. His famous analogy was a vending machine: you insert coins, press a button, and the machine delivers a snack. No cashier. No invoice. No "I'll pay you back later." The rules are built into the mechanism itself.

Szabo's vision stayed theoretical until Ethereum launched in 2015 and gave developers an actual platform to deploy code onto a blockchain. That's when smart contracts went from idea to infrastructure.

How It Differs from a Legal Contract

A legal contract is a written agreement that a court can interpret and enforce. It handles ambiguity reasonably well — a judge can read "delivered in a timely manner" and decide what that meant in context. But enforcement is slow, expensive, and depends on the legal system of whichever country you're in.

About This Book

If you are a high school or early-college student who has heard the words "blockchain," "Ethereum," or "smart contract" and wants to understand what is actually happening under the hood, this guide is for you. It works equally well for a student taking an intro computer science or economics course, a self-directed learner looking for a Solidity programming introduction at the high school or early-college level, or anyone who has tried to read the Ethereum whitepaper and bounced off the jargon.

This is a cryptocurrency and blockchain technology study guide built around one core question: how do smart contracts work, from beginner level all the way to the details that matter? The sections cover Ethereum blockchain coding explained simply — the EVM, gas fees, how Ethereum transactions work step by step, common smart contract bugs and security failures, and how DeFi and NFT technology works for students encountering these ideas for the first time. Short by design, no filler.

Read it straight through once, study the worked examples closely, then attempt the problem set at the end to confirm your understanding.

Keep reading

You've read the first half of Chapter 1. The complete book covers 6 chapters in roughly fifteen pages — readable in one sitting.

Coming soon to Amazon