Repetition and Complexity

A good TTRPG rule set is easy to use at the table, meaning that players and DMs don't have to look up many rules in play. The game flows from a limited set of core mechanics that, once learned, are easy to apply to any situation that emerges.

That sounds great, but like many things applying it to excess can hurt your design. If you have too few mechanics, play might feel flat and repetitive.

I think 5e uses advantage and disadvantage too freely. I can't see a target, and it has a defense spell, and there's a goblin distracting me. All three lead to the same outcome - disadvantage.

I've been thinking about this a lot as I revise the 5e engine. I want to make the game even easier to use, but I'd also like to add a little more tactical depth. Here's an example of how I am trying to do that.

I've played 5e at least as long than anyone (Literally! I ran the first playtests) and I still don't have the rules for light and obscurement down pat. Looking back on the design, they fell into a place where we felt we needed rules but didn't really want anyone to use them. So, they became this mishmash of simulation-ish stuff. I always have to look them up, because when I am stuck using them it's probably because something has gone wrong.

Over the years, I've come to appreciate using light as a resource in dungeon delves. I've also wished that 5e provided a little more tactical texture in its core rules.

With that in mind, I revised lighting, obscurement, and cover (along with invisibility) to push them off of advantage/disadvantage.

Lighting enables stealth and limits how far you can see. Obscurement does the same. The idea is to use these as tools to create encounters where movement and positioning are important. I also tightened up the amount of light shed by sources of light to better match spell and attack ranges.

If you can't see a target but it is not hidden, its AC is the higher of 25 or its normal AC. This keeps advantage and disadvantage as tools you can layer on top of a lack of line of sight.

Cover has a similar effect. It provides a boost to AC (making it 15 or 20, depending on the amount of cover). This means that heavily armored creatures don't need cover, but lightly armored ones become much tankier when they use it. The party's wizard now gets a lot more benefit from taking cover.

Here are the rules:

Vision and Light

Lighting and obscurement both play a role in determining how far you can see.

Lighting

There are three levels of lighting that you can encounter on adventures.

Darkness: You can’t see into darkness and creatures can hide in areas of darkness.

Dim Light: You can see in dim light, but the shadows allow creatures to hide here.

Bright Light: You can see in bright light, and there is too much light to hide.

Sunlight: Sunlight is a special case. Some creatures suffer drawbacks when they are in bright or dim sunlight.

Overlap: When determining the lighting in an area, any source of bright light makes an area brightly lit. If the only light is dim, then the area is in dim light. Otherwise, absent a source of light an area is in darkness.

Sources of Light

Each source of light typically sheds bright light in a close radius, and dim light in a broader radius. The bright and dim light radius are measured from the light source.

Source/Bright Radius/Dim Radius

Torch/5 feet/30 feet

Lantern/10 feet/50 feet

Candle/5 feet/10 feet

Darkvision

Darkvision allows you to see in the dark, though with some limitations. You treat darkness as dim light within range of your darkvision. Darkvision does not function while you are in an area of bright light or sunlight that is bright or dim.

Obscurement

Fog, steam, smoke, and foliage can hinder vision despite the lighting conditions. Obscurement reduces the distance you can see depending on how thick it is, but does not block attacks or spells.

Lightly Obscured: You can see up to 20 feet through an area that is lightly obscured. You are unable to see anything beyond that.

Heavily Obscured: You can see up to 5 feet through an area that is heavily obscured. You are unable to see anything beyond that.

Special Senses

There are three special types of vision that can help overcome darkness and obscurement.

Blindsight

Blindsight allows you to sense the presence of objects and creatures within range. You ignore darkness and obscurement within your blindsight’s range.

Darkvision

Darkvision allows you to see in the dark, though with some limitations. You treat darkness as dim light within range of your darkvision. Darkvision does not function while you are in an area of bright light or sunlight that is bright or dim. Obscurement blocks it as normal.

Tremorsense

Tremorsene all allows you to see a creature as long as it stands on the same surface as you within the range of tremorsense, ignoring both darkness and obscurement.

And here's a piece from the combat section, covering unseen targets and cover:

Determine Target AC

Most of the time you use the target’s listed AC, but some effects or situations can alter a target’s AC. The target uses the highest of the AC options available to it, unless it picks a lesser defense or opts for the attack to hit automatically.

Sight: If you cannot see the target but it is not hidden, its AC is the higher of its normal AC or 25.

Cover: Cover provides AC 15 if it shields up to half the target, and 20 if it shields more than half but still allows a clear path for the attack. Use the higher of the target’s normal AC or the AC provided by the cover.