Sneak attacks by well-prepared rogues outside of melee (such as lying in an ambush with a ranged weapon) will automatically add the Sub bonus to damage if the attack hits.
What about combat? Some feel that succeeding in sub+DEX to hide vs. sub+MIND to spot and then failing the attack roll is hard on the rogue.
Here’s a house rule to fix this.
If rogues join a melee where all enemies are already busy, they’re automatically flanking, ie. numerical superiority determines flanking. There’s no bonus for flanking, but if you’re a rogue, you automatically get the Sub bonus to damage in this situation.