Minecraft offers a free demo version that can be played online. While it has limitations, it provides a taste of the game.

Once you purchase Minecraft Java Edition, the official launcher lets you install any old version, including 1.12.2. Here's how:

The enduring popularity of version 1.12.2 is largely due to the "technical wall" created by the subsequent 1.13 "Update Aquatic". That update overhauled Minecraft's internal code so drastically—changing how block IDs and commands worked—that many complex mods were essentially broken. As a result, 1.12.2 became a frozen-in-time paradise where:

100% open-source, completely safe, and natively downloads modpacks from CurseForge and Modrinth. Step-by-Step Installation Guide

Mojang has made it remarkably easy to play any old version, mod the game deeply, and join a vibrant multiplayer community—all legally. If you truly cannot afford the game, use the demo, save up for a few weeks, or ask for a gift code on your birthday.

Keep your system defenses active during installation to scan downloaded game directories automatically.