From publisher blurb:
This is a collection of my own O5R house-rules for D&D. It's a blend of both old school, 5th edition, and my own special sauce.
Crimson Dragon Slayer D20 Revised (I'm just going to call it Crimson Dragon Slayer, if you don't mind) has a few design goals which I'll ennumerate here...
1) The rules are basic, minimal, and the system is d20 D&D. That makes it easy to understand.
2) If you have a luxury set of 7 dice, Crimson Dragon Slayer allows you to roll the dice you have instead of wishing you had extras. I can't be bothered to roll my d6 six times or d4 three times and add then altogether with everyone at the table waiting... or worse, rolling for me!
3) Most importantly - Crimson Dragon Slayer is D&D on arcade mode! That means it's specifically geared towards one-shots and short campaigns, generating maximum value here and now, without the frustration of never getting the best out of your character at some higher level.
You don't have to worry about getting down to half your HP or running out of spells/healing after the very first encounter. If prepared, your adventuring party can keep kicking ass until you've put in a full work-day, not merely 5-minutes. Save or die is badass... nap or die is bush league!