Download only from official sources
Use mayhempedia.com or the matching GitHub Release. The official Windows x64 installer for version 0.1.2 is Mayhempedia-0.1.2-setup-x64.exe.
Download and play safety
Verify first. Then play.
Mayhempedia is an unsigned public beta. This page explains exactly where the installer comes from, why Windows may flag it, and what the app does inside a League session.
Why Windows may show a warning
The beta is not code-signed yet, so Windows can label it as an unknown publisher. That warning is expected for this build. Do not install a copy you cannot trace to the official release and verify with the checksum below.
SHA-256: E6493ADC2A252C17723AF69220B7D3287193BEA732170CC0CCF968712AD6DE27
What happens in game
Mayhempedia reads local League Client state to identify a champion selection and present information. The overlay is display-only: it does not read game memory or automate gameplay, clicks, purchases, champion actions, or augment choices.
What stays local
Settings, custom routes, selected route preferences, and optional match history are stored on your computer. Mayhempedia does not ask for or store a Riot password. Read the complete privacy note.
Something does not look right?
Do not run it. Send the release link, screenshot, or problem description through GitHub Issues or Discord. We would rather investigate a report than ask a player to guess.