The Luck-Based Mission is a bane to many gamers because if luck is not with you, you'll lose. The worst examples are when skill is completely removed as a factor. Regarded as frustrating at best and often an infuriating stumbling point, the games that actually feature this as a requirement are thankfully few, but still, they're present. Save Scumming is a requirement. This trope is particularly vexing for speedrunners; gamers can pour as much practice as they want into perfecting skill-based portions of the game, but that won't stop their speedruns from being ruined by one bit of bad luck.