OSR Modifying 1E (OSRIC) with elements of 5E

[Ebon Shar]

I'm running an ongoing TOEE campaign using the OSRIC ruleset, but I've fallen in love with some of the rules elements of 5E. Dropping in Ad/Disadvantage seems a no-brainer, but it may be a bit more challenging to add additional elements.

Skills: My idea is to allow the players to select three area of expertise based on character backgrounds. From this list, I'll allow a +3 to skill rolls as applicable.

Checks/Contests: This will be a bit tricky because it involves importing 3E/4E stat bonuses. As long as the bonuses are used exclusively for checks/contests, this does not present a problem, but how to deal with exceptional strength? Additionally, how should I adjudicate such things as stealth and perception without completely ignoring the system as it's written in 1E? Should I ignore that subsystem entirely and just assign bonuses to thieves and assassins?

Saving Throws: At this point it seems sensible to just use the existing system.


Am I overlooking any obvious contradictions/problems? I'd love to hear some ideas as to how to make this transition as smooth and seamless as possible.

 

[Lanefan]

Can't help witht he rest of your questions, but...

Checks/Contests: This will be a bit tricky because it involves importing 3E/4E stat bonuses. As long as the bonuses are used exclusively for checks/contests, this does not present a problem, but how to deal with exceptional strength?

Break out each gradation of exceptional strength into its own full number - this puts 18.00 at 24 and Hill Giant strength changes from 19 to 25, with everything else following suit. Then use the corresponding bonus, as normal.

Additionally, how should I adjudicate such things as stealth and perception without completely ignoring the system for such as it's written in 1E? Should I ignore that subsystem entirely and just assign bonuses to thieves and assassins?

Stealth: the "move silently" mechanic from 1e is fine for this. Perception: trickier. I always use a d20 roll-under, modified just about every single time depending on what class/race of character is rolling, what the situation is, etc.; but it's very much a wing-it system as it sort of has to be given all the constantly-changing variables.

Lanefan

 

[ren1999]

Ebon, consider this when converting.

When the monster attacks, what number on a 1d20 is needed to hit after the bonuses are applied?

If the character has an AC of 20, and the monster attacks at 1d20, then the monster will need to roll a natural 20 to hit. Now add bonuses to the attack. 1d20+3 means the monster will need to roll a 20, 19, 18, or 17 to hit.
Give the monster an ability score that gives them that bonus.
If the ability score exceeds 20 for humanoids or the limit for that particular monster, consider adding magic weapons or items as long as it's believable.

I was told that bonuses exceeding +10 are not going to be in 5th edition. So make sure that none of the abilities even with added magic exceed that.

What you don't want is for a monster to only be able to hit on a natural 20. That isn't very exciting or challenging.

 

[Remathilis]

Checks/Contests: This will be a bit tricky because it involves importing 3E/4E stat bonuses. As long as the bonuses are used exclusively for checks/contests, this does not present a problem, but how to deal with exceptional strength? Additionally, how should I adjudicate such things as stealth and perception without completely ignoring the system as it's written in 1E? Should I ignore that subsystem entirely and just assign bonuses to thieves and assassins?

I tend to treat Exceptional Strength as just an 18, with the benefit of having better "adjustments" than a non-fighter could. If two warriors with 18/XX scores form a contest, exceptional strength breaks ties.

There is already a sorta rule for stealth; its called surprise rolls. Elves and halflings get a bonus to surprise, thieves can make their HS/MS rolls to gain additional bonuses (a halfling in non-metal armor making his HS/MS is -8 to surprise!)

Likewise, I'd treat perception as a 1d6 roll; a 1 indicates success in finding stuff. It melds nicely with the already there rules for secret doors and listening. You could allow perceptive demi-humans (elves for example) a 1-2 on a perception roll to find/notice things as well.

 

[GX.Sigma]

From the 3e conversion manual:

Exceptional Score          New Strength Score

18/01–18/50                19
18/51–18/75                20
18/76 –18/90               21
18/91–18/99                22
18/00                      23
19–20                      24
21–22                      25
22–23                      26
24–25                      27

 

[Libramarian]

Additionally, how should I adjudicate such things as stealth and perception without completely ignoring the system as it's written in 1E? Should I ignore that subsystem entirely and just assign bonuses to thieves and assassins?

Do you mean the surprise rules? I much prefer 1e surprise. The monsters actually surprise the PCs sometimes. If your surprise rules are basically "DM decides when a group is surprised" like in DDN, they're not going to be a dick about it, so the monsters never randomly get the drop on the PCs. They just sit there while the PCs observe them and then decide what to do.

e.g.
Players: OK we open the door.
DM: You see some orcs eating dinner, what do you do?

Using the 1e surprise rules, it might be:
Players: OK we open the door.
DM: *rolls for surprise* You get a javelin in the face.

 

[dagger]

Using the 1e surprise rules, it might be:
Players: OK we open the door.
DM: *rolls for surprise* You get a javelin in the face.

Always oil the hinges!!