Olde Swords Reign - Core Rules

Olde Swords Reign is a tabletop roleplaying game based on 5th Edition but designed with emergent gameplay in mind. It’s faster, a tad deadlier, and relies more on player creativity to problem-solve than the options on a character sheet.
Universal mechanics run through the game that speed up gameplay, make improvisation easier for both players and GMs as well as helping to make rulings a little more intuitive and consistent.
You can pick up and play any old-school module or OSR adventure but still have that 5e framework.
Being based on the 5e ruleset, it can be played with any of the bigger Virtual Table Tops (VTTs) that have 5e rulesets and most of the rules can also be easily dropped into your regular 5e game.

What Are Some of the Differences Between 5E and OSR?
Simplified Classes and Races - Only 4 classes and 4 races but all have a huge amount of flexibility
No Subclasses - Subclasses are gone, speeding up character creation and allowing you to change direction as your character develops
Classes stop at level 12 - This is a game of adventurers, not superheroes. You get what you earn, and if you’re lucky, retire as a legend.
Skills Replaced by Backgrounds - Who you are and what you know matters. Add your proficiency bonus to any non-combat related checks that relate to your background, this, combined with straight ability checks replaces skills.
Feats & Hindrances - The feat system allows you to create any character concept you can come up with using the 4 base classes. Hindrances add a little more flavor to make your character a little more creating more opportunities for shenanigans.
Simplified Difficulty Classes (DC) - An intuitive fixed DC system makes ruling much easier.
Simplified Range and Movement - Movement and Speed are split into simple ranges
Spell Lists - Over 120 spells that go to level 6.
Monster Hit Dice - Monsters all have d8 Hit Die, like the original rules supplements.
Simplified Monster Creation and Conversion - Monsters XP, to hit bonus, saving throw, and more are all based on their Hit Die, making running, converting and creating them a breeze.