Missiles as Default

In general, D&D players assume that melee combat is the order of the day, with attacks from a distance usually offered by mages. This is all fine, but as a thought experiment I invite you to wonder what a ranged-focused ruleset might be. There are many examples of this in other games, where rifles or laser-pistols are the norm, but as a parameter of this challenge I will keep the generic fantasy setting.

James Lewis-Vines

1. 
   There is no single value for ranged skill. An archer might use strength to increase damage, dexterity to load quickly, and wisdom to aim true.
2. Cover is assumed to be used in most combats, and are the main form of defense.
3. Close combat uses fiddly rules and is not distinguished from grappling. 
4. In the equipment section of the rulebook, there is a table for "weapons" and "hand-to-hand weapons."
5. Close combat is typically the purview of unintelligent animals and violent outsiders. A peasant is more likely to own a sling than a spear.
6. Long-time players will advise new players that they don't want to be caught out without a hand-to-hand weapon.
7. The average dungeon room size balloons.
8. The range of many abilities, like sneak attack or turning undead, increase by an order of magnitude.
9. Wandering monsters are never too "primitive" to reach for a sling, atlatl, or good throwing rock.
10. Mounted combat is fleshed-out and does not assume you want to make a cavalry charge.
11. No short/medium/long range distinction. Instead, a penalty for indirect fire.
12. Internet forums bloat with criticisms of the rulebook's improper use of archery terms.
13. Damage types in general are less important. Almost nothing is immune to piercing damage.
14. The fighter class shoots on the run, reloads quickly, and uses distinctive fetching instead of parrying, maneuvering, or making notches.
15. The thief class is essentially a ranger, and acquires the vaunted ability to escape from melees.
16. Descriptions of relevant spells highlight how they can be used for force a foe out of cover.
17. A well-researched samurai replaces the paladin class.
18. Simple rules for how far away your shout can be heard are enforced in wide-open engagements.
19. Stealth is usually performed acre-by-acre, not room by room. Sneaking through a guarded manse is either impossible or requires the DM to improvise.
20. You cannot make attacks while prone.
21. It is common to negotiate with your villain through messengers, which many DMs handwave and treat like a face-to-face conversation.
22. In nautical campaigns, pirates are feared because they will actually try to board your ship.