Google Calendar Sync Builder

Pick the game sites you use and fill in their details. You'll get one Google Apps Script that keeps your Google Calendar in step with them: it adds new sessions, updates changed ones and removes cancelled ones.

Everything happens in your browser. Nothing you enter is sent to Loodingdongs; your entries are only remembered on this device so they're here next time.

Your calendar

Shared by every source below
primary is your main calendar. To use another one, paste its name or its Calendar ID (Google Calendar → Settings → the calendar → Integrate calendar).

Warhorn

Atom schedule feed, with waitlist tracking
Sign in to Warhorn, open your upcoming games, click the RSS button, and copy that link. It contains your access token, so keep the finished script private.
Confirmed color
Calendar's color
Waitlisted color
Calendar's color
Events appear as [Warhorn] Session name, or [Warhorn][WAITLIST] Session name while you're waitlisted. The color switches when your status changes.

StartPlaying.games

iCal player calendar feed
Sign into StartPlaying, open My Calendar, click Subscribe, and copy the calendar link. A webcal:// link is fine; it's switched to https:// for you.
Event color
Peacock
Events appear as [SPG] Game name.