D&D 5E Handling Grenade-like Weapons with AoE/Splash Damage?

[BuddyRich]

So far Im really liking 5E but have come across an inconsistency of sorts and was wondering if there is a RAW way to handle it I am missing.

So in PHB you have Holy Water/Alchemists Fire which I assume to be vials of liquid that can be tossed at a foe. PHB says to handle them as improvised weapons, which infers a "to hit" roll against a target AC.

OTOH I am running the Kobold Trap Lord in B2 from the playtest who has a "fire bomb" which is all intents and purposes is a grenade. The DMG does have a section on explosives and it seems you can basically toss the grenade wherever you want and it hits everyone in its AoE with a saving throw to evade some of the damage. No "to hit" roll involved. This makes sense as you don't necessarily want to hit a specific target, just an area and let the blast get them.

Some of my players think I needed a "to hit" roll anyway, so I did, targeting the mage who happened to have the lowest AC, and hit, but then one player thought I needed a separate "to hit" to hit them as they were in the blast radius, which I disagreed with. They certainly got their saving throw to evade some damage but I wouldn't need to hit them, I wasn't targeting them.

Which brings up something that's always been silly. Take the same situation and call them spells. Any single target beam sort of spell generally requires a "to hit" roll against a target AC but a fireball always always hits it intended detonation point (be that a character or the square they occupy). 5E does nothing to change this. Personally I am fine with this. With a fireball I am not aiming for a specific character but an 5' square, its not moving or dodging, so its an easy target and its "magic". A beam usually requires it to hit a character for it to work, hitting the ground with the beam does nothing.

Throwing something OTOH would still require a bit of skill. I don't always hit the bocce when I toss something. So I could see requiring a to hit... but how to handle a miss on something that explodes? Chances are the intended target is still within the blast radius anyway, though it might be under thrown and also hit friendlies, etc. but that is asking for more complication (though perhaps fun as a once-off). Being more of rules-lite DM I want to just say grenade-like weapons hit their detonation point wherever its intended, but I want to be fair to the players. Are there rules I am missing on this so I can point them out to the one player who is more of a stickler. I can cite the DMG or the PHB to support either.

 

[Voort]

Skip the attack roll, just give the PCs in the detonation area a saving throw for half damage. I'd treat a hand grenade just like a Thunderwave spell centered on the target square.

 

[Paraxis]

Skip the attack roll, just give the PCs in the detonation area a saving throw for half damage. I'd treat a hand grenade just like a Thunderwave spell centered on the target square.

Thunderwave is not centered on a square, it shoots out from the caster in a 3x3 cube adjacent to him.

For grenades, I would use an area of effect save system like for spells not a to hit roll. If you want to add a to hit roll I would make them Target AC 10 and for every 1 they missed it by have it travel a few feet in a random direction, just roll a d8 with directly north of the target as '1' and go clockwise around the compass points.

 

[EvanNave55]

Thunderwave is not centered on a square, it shoots out from the caster in a 3x3 cube adjacent to him.

For grenades, I would use an area of effect save system like for spells not a to hit roll. If you want to add a to hit roll I would make them Target AC 10 and for every 1 they missed it by have it travel a few feet in a random direction, just roll a d8 with directly north of the target as '1' and go clockwise around the compass points.

This is exactly how splash potions worked in PF, though with the new bounded accuracy causing ACs to lower I might reduce that some (5-7 maybe)

 

[Shiroiken]

Use 1E rules. On a miss roll 1d8, with "1" being the space in front of the target (under-thrown), and each higher number being a different space clockwise. The area hit will suffer the damage, and (if you feel the need) a creature in the hit space has to make a Very Easy Dex Save or take 1/2 Damage (it's both easy and less damage since it's a splash, not direct hit).