Rules Cavernous Walls: Depicting Caves and Tunnels with Squares

[Smeelbo]

Cavernous Walls: Depicting Caves and Tunnels with Squares

When I first read the Kobold Keep adventure, I was disappointed that it was all straight lines and right angles. My favorite introductory scenario involves rooting kobolds out of a silver mine, and I wanted a way to depict caverns and twisting passages in 4E. However, 4E combat depends fundamentally on squares, so I can't really use hexes, partial squares, and so on.

So here is my proposal for representing non-straight tunnels and caves using squares and right angles.

Cavernous Wall:

If both you and a non-adjacent target are adjacent to the same Cavernous Wall, and all lines of effects pass only through squares adjacent to that same Cavernous Wall, then the target has Cover if within 5 squares, or Superior Cover if further away. Corners between two Cavernous Walls provide Superior Cover.

Simple, elegent, and easy to explain. At the same time it accounts for blocked lines of sight arising from curves of the tunnel and their uneven walls, but is depicted on the battle mat as squares and right angles. Easily depicted, too: I can use a jagged line to indicate a Cavernous Wall on the map.

So I can use a simple straight 5' or 10' corridor to represent a winding tunnel, right angles for branching tunnels, and large rectangular rooms for large but rough caverns, add the occassion difficult terrain for rubble or other obstacles, and viola!

I do realize that this is very bad terrain for some characters. It rewards melee and sneakers, and punishes ranged powers. I wouldn't use it all the time. However, it does seem an elegant way to depict windy ways and rough hewn caverns.

Smeelbo

[Fredrik Svanberg]

Sounds good to me.

[dammitbiscuit]

Side note: hexes work great. In the likely event that there will be square, gridded maps that you absolutely love and want to use, invest in a simple sheet of transparent paper with thin, white hexes on it.

Bursts and blasts have to be re-shaped, but the players find that cone-shaped blasts are more evocative anyways.

[Smeelbo]

I've thought about it some more.

The essence of the idea is that I want a wall that acts like a corner, that is, it provides cover.

As posted, the rule has some unintended boundary effects, specifically that a character can see further into a passageway with cavernous walls from outside the passageway than in it, because one character is not adjacent to the cavernous wall.

If the wall acts like a corner, that is easy enough. I can draw such walls like --^--^--^--^--^--. Then count the number of corners between the two characters. If it's more than one corner, it grants Cover, and five or more corners grants Superior Cover. This eliminates many of the boundary issues.

Indeed, "cornery" walls conveys the essence of a twisty passage.

Smeelbo

[Smeelbo]

Cornery Walls: Count the number of squares adjacent to Cornery Walls between the attacker and the target, not including the squares they occupy. If there is at least one such square, then the target has Cover, if there are at least four, then the target has Superior Cover.

Tested this out last night, and it went exactly as I had hoped. Ranger and Rogue sneaking down dimly light tunnels scouting out a back way into the Goblin Fortress. It allowed for good but not perfect sneaking. More than once, the hidden Rogue and hidden Goblin guards bumped into each other, which was a great way to start combat. It even allowed a modest amount of sneaking partway into a "cavern," that is a room with cornery walls.

There was a little running back down the tunnel to hide during combat, but no more than if you had a regular bent corridor to duck behind, and it was costly in terms of time out of combat.

I am very happy with how this rule performs: it gives me the feel of curving rough walls while using the standard 5' square and right angles. I will be using this when I DM.

Smeelbo

[Sabathius42]

Easy to understand - Check.
Allows more interesting encounters - Check.

I will file this one away for the next time I run a game.

DS

[PrecociousApprentice]

I play mostly PbP, so this would be really easy to incorporate into a Excel map for play. I like it. It took me a moment to get what it did, and why, but it does get at what you want and in a relatively simple way. Nice.