Fair facing house rules for 5e

Question

I am a bit disappointed by the lack of tactical positioning in 5e, as evidenced in questions such as Are melee combatants limited to standing around saying "I attack"?.

I have tried porting flanking from 3.5e into 5e, but I was not happy with the results. Therefore, I decided to use a facing house rule, partially based on the suggestions in the 5e DMG p.252.

Facing house rule

Each creature chooses one corner or side that they face.

Foes in red squares have advantageous facing to the creature in the green square. Attacking (melee, ranged) and casting spells with advantageous facing applies facing modifiers.

Facing Modifiers

• -2 to green AC vs red
• -2 to green DEX saves vs red

Turning and moving

Turning is changing the facing by more than one tick.

• Turning after moving at least one square is free.
• Turning without moving costs 1 square of movement.
• Difficult terrain and other modifiers increase the cost as usual.
• If green moves backwards into red squares, without turning, it costs +1 square.

Opportunity attacks

Green provokes an opportunity attack

• …by red, when green enters or leaves a square that is threatened.
• …when green leaves a square that is threatened by a foe that turned red by the movement.

Green does not provoke an opportunity attack

• …by white, when green enters or leaves a square that is threatened.

Creatures in red squares do not provoke opportunity attacks from the creature in the green square.

Targeting

• Green generally cannot target red squares
• Area of effect spells can extend into the red area if targeted on a white or green square/corner.
• For facing modifier considerations, area of effect spells use the point of origin as shown in PHB p204, facing from the point of origin to the boundary.

Additional rules

• Critical hits from red squares against green deal an additional die in damage.
• Creatures in red squares do not get disadvantage for close ranged attacks.
• A shield offers no protection against attacks from red squares.
• Green Wisdom (Perception) against red Dexterity (Stealth) checks may have disadvantage.
• Some monsters (mainly non-humanoids such as beholders) may have different facing rules.

My goals

My goal is to make tactical positioning more important in 5e. However, an equally important goal is that my changes do not favour certain classes far more than others.

I did add the DEX penalty for this reason: Blasting spells should work similarly to physical attacks, and a well positioned blaster should get similar benefits.

On a side note, the rules should also be clear and fast, which is why the delineation between the red and white squares is a straight line over the battlefield.

My question

What parts of my house rules are unfair in the sense that they benefit/hurt only specific classes in a non-trivial way? I am willing to allow minor injustices, but they should not nerf a character concept or optimisation strategy into worthlessness.

A good answer would contain a mechanical explanation of which specific changes are bad for what classes. I am not looking for general discussions of tactical positioning or flanking. An answer that shows that facing is incompatible in general with my fairness goal however would be good.

Answer 1

If I understand your system correctly, it will give rogues an automatic way to activate Sneak Attack:

The green character is the Rogue and the blue one is an enemy. On his turn the rogue steps two squares to get behind the enemy and turns for free. He attacks (with advantage, -2 to enemy AC, and possible more reduction due to the shield), activating Sneak Attack, and then gets to step back two more squares using his leftover movement.

On top of this you should consider things like whether a fighter can riposte to an attack done from the red zone.

Is an enemy/ally in red zone considered to be visible? For example Rogue's Uncanny Dodge says (emphasis added)

when an attacker that you can see hits you with an attack, you can use your reaction to halve the attack’s damage against you.

Can a rogue still activate it while being attacked from behind?

Answer 2

We had two long (8h) session where we tried the facing rules, once on squares and once on hexes.

The players were a Death Cleric, a Vengeance Paladin, a Bard, a Blaster Warlock and a Psion Mystic (from the Web/UA).

We did not notice any specific problems or disadvantages to specific classes, and the fights were quick. It did allow me to do some nice tricky set-piece battles using the geography against the players in such a way that they had to do clever tactical decisions to avoid putting enemies into red squares.

However, after these two sessions, I decided that we will go back to 5e standard rules for movement and OA. We stopped because I felt that only the mechanically interested players (half of the group/those that read the PHB by themselves) were really on board, while the other half disliked the additional complexity, and simply asked others "can I do this?" or "should I do that?".

So my short play-testing of the rules showed that they are viable for the right group, but that group unfortunately would be only 3 of the 5 players I have now.

Answer 3

As suggested in the comments, I'll make my initial thoughts into an answer.

Firstly consider Relentless Avenger, Vengeance Paladin class feature (PHB p88):

When you hit a creature with an opportunity attack, you can move up to half your speed immediately after the attack and as part of the same reaction. This movement doesn't provoke opportunity attacks.

So in a three on three combat, one of the monsters moves away and the Paladin hits with an opportunity attack. He can then move through the vacated space in the lines for free and ensure the other two monsters are flanked.

There is little defence against this and he can do it whenever someone provokes an opportunity attack. This gets more effective coupled with feats like Mage Slayer or Sentinel that offer more opportunity attacks.

I also think these rules make teleporting much more effective and would be very careful with Way of the Shadow Monks, due to Shadow Step (PHB p80):

When you are in dim light or darkness, as a bonus action you can teleport up to 60 feet to an unoccupied space you can see that is also in dim light or darkness. You then have advantage on the first melee attack you make before the end of the turn.

These guys can not only escape flanking with ease, but can very easily initiate it for no resource cost every turn, making a mockery of dungeon corridor fighting.

Other, resource driven, teleports will also be great using these rules but Shadow Step takes the biscuit.

I'd be interested to see a ruleset like this work. Knowing the people I play with however, they're quite easy to exploit for some classes.

Answer 4

As I have shown in my other answer, this system allows for some unreasonable things to happen: a rogue can walk behind an enemy in plain sight and sneak attack while the enemy is just standing there without doing anything. I have thought of a modification of your system based on awareness.

1. Awareness represents whether the position and actions of the creature that has the turn (Character) are known by another (Opponent).
2. Opponent that is unaware of Character suffers penalties
   • Character has advantage on attack rolls versus Opponent
   • Opponent has disadvantage on saving throws against Character's actions
   • Character is considered as "not visible" by Opponent. For example, Character's movement doesn't provoke opportunity attacks, and Opponent cannot use rogue's Uncanny Dodge
   • ...
3. Once an Opponent is aware of Character the awareness lasts till the end of the turn unless
   • Character becomes invisible or hidden
   • Opponent loses vision
   • ...
4. Opponent is aware of Character if
   • Character starts their tun within 5 ft from Opponent
   • Opponent can see or otherwise sense Character in the beginning of Character's turn or at some time during the turn. The vision zone is organised same as in the question. If Opponent took a dodge action on their turn, they can see in all directions.
   • Opponent was attacked by Character they would be able to see if they looked around, or by a character that is within 5 ft from them. For example:
     1. a fighter attacks opponent from behind, opponent becomes aware of the fighter and following attacks against the same opponent are done normally (no disadvantage and so on)
     2. same fighter under the effect of Greater Invisibility still makes the opponent aware of them after the first attack.
     3. same fighter under the effect of Greater Invisibility shooting arrows from distance makes all attacks with advantage and so on.

I think such system makes more sense for the types of battles that happen in D&D. Tactical positioning is more about battles between armies when you have soldier formations that cannot quickly adapt (e.g. turn their facing as a whole).