Would changing Surprise to just give Disadvantage on Initiative checks overlap with any existing sources of Disadvantage?

Question

In an effort to make the game more interactive, I'm strongly considering house-ruling the Surprised condition to read "this creature has disadvantage on initiative rolls" instead of outright skipping their turns.

For reference, the SRD defines Surprise as follows:

If you’re surprised, you can’t move or take an action on your first turn of the combat, and you can’t take a reaction until that turn ends. A member of a group can be surprised even if the other members aren’t.

Would this house rule make any existing mechanics redundant or obsolete? What other things grant disadvantage to initiative?

Answer 1

The following mechanics would be affected:

• Its possible that a surprised person with a high initiative modifier and/or who got lucky might act first; totally nerfing the use of stealth by their opponent.
• Spending inspiration will negate the effects of surprise totally for PCs
• The ability to take reactions before your turn when surprised is a huge benefit. Being able to take an opportunity attack cuts down movement options for the surprisers and being able to cast a Shield spell is golden.
• You eliminate the possibility that the non-surprised people may act twice before the surprised person acts - this will make surprise a much less dangerous situation all around.
• It would make the assassin roguish archetype pretty useless

Existing mechanics made redundant or obsolete?

Surprise (and by extension Stealth) is effectively redundant or obsolete. It would have almost the same effect and be much simpler if you just eliminated surprise altogether.

What other things grant disadvantage to initiative?

Anything that gives disadvantage to a Dexterity check gives disadvantage to Initiative because initiative is a Dexterity check. Worth noting, in passing, that certain classes "Jack of All Trades" ability gives half proficiency on initiative checks as it is an ability check in which you are not proficient.

Answer 2

Recall that initiative is a Dexterity check. So yes, your Surprise houserule would overlap with plenty of things.

There are plenty of ways to incur disadvantage on a DEX check. Some include:

• any level of exhaustion
• poison
• frightened
• the Contagion spell
• Bestow Curse or Hex (if the caster chooses DEX)
• &c. &c. &c.