Li Shenron
Legend
This is not exactly what you mean with your question but, here's something from previous editions I may use in 5e:
- specifically for playing Rokugan adventures in 5e, I will use a variety of 3e/d20 rules (some adjustments needed) e.g. Iaijutsu, Honor, Taint, Void Use...
- I may re-use some 3e spells, skills, feats and prestige classes, but hardly ever without serious adaptations
3e smaller feats fit quite well in 5e now that we've seen a large trend of 5e feats which are in fact half-feats, granting 1 ability increase alongside the main feat's benefit. Thus it's easy to allow an older 3e feat in place of one of the 2 ability increases. That doesn't mean any specific 3e feat will be appropriate, in fact most of those granting sheer bonuses probably aren't - need to check each feat before allowing it!
- specifically for playing Rokugan adventures in 5e, I will use a variety of 3e/d20 rules (some adjustments needed) e.g. Iaijutsu, Honor, Taint, Void Use...
- I may re-use some 3e spells, skills, feats and prestige classes, but hardly ever without serious adaptations
3e smaller feats fit quite well in 5e now that we've seen a large trend of 5e feats which are in fact half-feats, granting 1 ability increase alongside the main feat's benefit. Thus it's easy to allow an older 3e feat in place of one of the 2 ability increases. That doesn't mean any specific 3e feat will be appropriate, in fact most of those granting sheer bonuses probably aren't - need to check each feat before allowing it!