In 5e, if a Grease spell is cast and a large (eg. 10'sq facing) creature is killed on it, covering the same area as the spell, could other players/NPCs/monsters walk over that creature as if the Grease spell does not exist?

  • 1
    \$\begingroup\$ Are you asking as the player or as the DM? In other words, are you looking for a way to make a ruling for your players, or, are you trying to make a point to,/,with your DM about something that happened in game? Welcome the RPGSE, Paul. The tour, help center, How to Ask and How to Answer provide guidance on the best way to use the SE format. A key to that is to consider, in presenting a question, "what problem am I trying to solve?" \$\endgroup\$ Commented Mar 3, 2021 at 13:15
  • 1
    \$\begingroup\$ Thank you for your kind welcome. I was trying to be neutral in order to allow for both perspectives to be considered. This thing happened and I was interested to see if there were any views on it that we could take into our game. \$\endgroup\$
    – Paul
    Commented Mar 3, 2021 at 13:40
  • \$\begingroup\$ I am glad that you found the answer useful. Hope to 'see' more of you; we have a wealth of RPG experience in our various Q&As here, and not just about D&D. 😊 \$\endgroup\$ Commented Mar 3, 2021 at 13:49

1 Answer 1


The rules do not say

Here's the spell description:

Slick grease covers the ground in a 10-foot square centered on a point within range and turns it into difficult terrain for the duration.

When the grease appears, each creature standing in its area must succeed on a Dexterity saving throw or fall prone. A creature that enters the area or ends its turn there must also succeed on a Dexterity saving throw or fall prone.

There is no rule "grease spell effect is negated when a large creature is lying upon" in any official source book. We on the internet can only tell you that spells do based on the books, because we are not DMing your game. We cannot change or expand upon the rules and say "this is part of how the spell works". We do not have that authority; the DM of the game does, and we aren't that.

Large creatures are not 10ft wide

The Grease spell covers 10-foot square, and a large creature does not cover 10-foot square:

A creature's space is the area in feet that it effectively controls in combat, not an expression of its physical dimensions. (PHB p. 191)

Keeping in mind that a large creature isn't a 10 x 10 square object, the DM may, for example, call for a Dexterity (Acrobatics) check for walking along the irregular surface that is the prone body.

Nothing states that you can't though

"There is no rule for that" does not equal "you can't do that". Player characters can (and probably should) do perform actions not detailed elsewhere in the rules:

When you take your action on your turn, you can take one of the actions presented here, an action you gained from your class or a special feature, or an action that you improvise.

When you describe an action not detailed elsewhere in the rules, the DM tells you whether that action is possible and what kind of roll you need to make, if any

(PHB p. 192 , emphasis mine)

You can try to walk over it, but the result will depend on the situation — how exactly the creature is lying, what body does that creature have, et cetera. This is the DMs job to adjudicate such things, so it becomes exactly the "ask your DM" type of question.

One thing we can say though — there is no "fluff" ignorable text in that description. It says "slick grease covers the ground", therefore this slick grease is the exact reason why a walking creature "must succeed on a Dexterity saving throw or fall prone". If you completely cover the grease with something big and heavy enough to provide a sound surface, it probably negates the spell effect (but still, ask your DM).

  • \$\begingroup\$ Nice edit. +1 😎 \$\endgroup\$ Commented Mar 3, 2021 at 13:16
  • 2
    \$\begingroup\$ Very helpful and insightful. "It depends on the situation" I think is the best way to consider it and a good bit of player/DM conversation can only add to the game. \$\endgroup\$
    – Paul
    Commented Mar 3, 2021 at 13:45
  • 3
    \$\begingroup\$ Just to emphasise the part about large creatures not filling a 10' square. The size rules are about how much space a creature controls while "in combat", not their physical size. Most humans aren't 5' wide for example! (Exception for the Gelatinous Cube :). Plus it may be not much easier to walk on an uneven squishy dead creature than on a grease spell. \$\endgroup\$
    – PJRZ
    Commented Mar 3, 2021 at 14:00
  • \$\begingroup\$ @Paul in comparison to the previous editions, 5e really favors the "rulings over rules" principle, so "it depends on the situation" (equals "ask your DM") is a valid answer to may questions initially posed as questions about the rules. \$\endgroup\$
    – enkryptor
    Commented Mar 3, 2021 at 20:16
  • \$\begingroup\$ One note: I'd argue that in the case a Large creature covers the slippery grease, it's still difficult terrain (depending on anatomy and armor considerations) so while a creature wouldn't have to make a Dex save, they're still not moving unimpeded through the space. \$\endgroup\$
    – raithyn
    Commented Mar 3, 2021 at 22:34

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .