2021-05-26, 08:49 PM (ISO 8601)
Re: [Classic D&D/OSR] Proficiency bonus
5e's Proficiency system will begin to break down for your monsters IF you use the 5e points standard. The problems will start around 5th level and continue to grow using 5e's progression. The simple fix is to change the numbers so bonuses match up more closely to older D&D and AD&D Level power scaling. for example:
Originally Posted by paladinn
Level 0 = 0
1st Level to 2nd Level = +1
3rd Level to 5th Level = +2
6th Level to 9th Level = +3
10th Level to 14th Level = +4
15th Level to 20th Level = +5
In addition, IF you are keeping the 5e limit of 20 on characteristics, you might change Characteristic/Attribute bonuses to something like:
1 to 3 = -3
4 to 6 = -2
7 to 9 = -1
10 to 12 = 0
13 to 15 = +1
16 to 18 = +2
19 to 21 = +3
If you are using RAW Characteristic, use whatever table is provided by the game.
This should allow you to play an OSR game using 5e's base mechanics (AC, Proficiency, Characteristic Bonuses, etc...).
For Proficiency, 5e's system is VERY GOOD and beats AD&D2e's roll under system by a mile. IF you want to use 5e's Proficiency, use the following system to help you integrate the bonus and penalty system from OSR. This Proficiency system applies to weapons as well as "skills."
NONPROFICIENT: -2 on the task. Ability bonuses may offset this penalty.
BASIC PROFICIENCY: No penalty but you will not improve in your chance to do a thing because you don't train enough. Ability bonuses apply as a form of "natural talent."
ENHANCED or MARTIAL PROFICIENCY: You get your Proficiency Bonus AND any ability bonuses added to any roll. Your Proficiency will increase as you Level up.
Since there are NO FEATS in OSR games, here is a cool way to add a FEAT or Special CLASS ABILITY to them. Have the player select the FEATS you have prepared for their Class. IF the FEAT is a skill-like FEAT, have them just roll a Proficiency check to succeed in using it (I do this with Spellcasting in my games). IF the FEAT is related to COMBAT (Disarm, Trip, Distract, Outmaneuver) have them roll a Proficiency check die [D20] WITH the attack roll die. Set the DC as either the monster's AC OR add to this DC based on the monster's resistances or bonuses (INT or WIS bonuses, for example). IF the attack roll fails, so does the Special Combat Maneuver. IF BOTH rolls succeed, the maneuver also works on the monster and it is Tripped, Distracted, or Disarmed!
IF you'd like to try an "off the shelf" OSR that uses 5e mechanics, I'd suggest you look at FIVE TORCHES DEEP. This RPG is a very good blend of OSR and 5e.