The Culture: From Fresh Initiate To High Priest

The Cleric and the Druid also share a certain set of elements. In their case, their careers focus around the establishment and development of a sacred space; this place is akin to the sanctum that Magic-Users and Illusionists require. All of their spell resarch and item creation requires such a space to operate, and as they reach Name Level it also becomes a place of temporal power- especially for the Cleric.

What marks the difference between these two and the latter pair is that, more often than not, the Cleric and the Druid's expansion of their scope of operations brings them into conflict. The Cleric--regardless of what god he serves--serves a force that, at best, co-exists with the natural world; the Druid serves that same world as its divinely-empowered agent.

This is because, being divinely-empowered agents, their sacred spaces are not just secure locations to do magic research and artiface. They are centers of religious observance, ritual, and practice and thus cannot avoid getting involved in worldly affairs as much as any ambitious Fighter, Thief, or Assassin.

The Young Initiate

Early on the Cleric and Druid will either operate out of an existing sacred space, or they will establish a small one that they alone can handle when not in the field.

Spell Research goes on here, and so does administering to the followers of their faith in that area. If they are working under an established authority--more likely for Druids than Clerics--they will also be getting briefed and debriefed by their superiors, superiors that will have a say in their fieldwork, and they are also likely to be introduced to other players in the .

Those acting independently will have barely a shrine to work with initially, and maybe not much in the way of followers, but--for Clerics in particular--the growth of a specific sacred space and follower body coincides with ther advancement up the levels. Both parties in particular will want to recruit specific talents out of their followers to assist with their magical activities as well as their religious callings.

Breaking In Their Robes

Clerics, upon creating a(n) (un)holy water basin as per pages 114-115 of the Dungeon Master's Guide at 5th level (at the earliest; Half-Orc Clerics can't do this as they are capped at 4th), enter the mid-game of their career. Now they become able to create (Un)Holy Water, and with acquisition of crystal vials that the Cleric Blesses/Curses is able to preserve (and thus sell) them.

Druids at this level gain access to their shapeshifting power as well as spells like Call Lightning, meaning that their range of potency now greatly increases and with that so does their ability to maintain the safety of their sacred space- as much by further obscuring it as by anything else. (When you need to fly, swim, or burrow in or out it cuts down on the odds of hostiles reaching it.)

Their expanded capabilities come with expanded duties, responsibilities, and authority because religion does not exist in a vaccum. They will be called up by followers to deal with their issues, they are now in regular contact with divine agents of their gods (because those are the parties that grant 3rd-5th level spells), and therefore they will be caught up increasingly in the dealings of their institutions as well as their divinities- more direct conflict of a supernatural nature occurs.

With scroll creation at 7th level, Clerics and Druids now gain the ability to do like Magic-Users and Illusionists and spend time preparing scrolls prior to taking to the field; these will likely be of spells that are good to have handy, but not at the expense of what is more commonly prepared. (No one complains about the Cleric preparing Raise Dead scrolls in downtime.)

They may also participate in potion creation, which is why having a friendly Magic-User (who does the actual creation, see DMG p. 116-117) is a wise relationship to cultivate; being able to heal or cure magically without expending spell slots is invaluable to managing the logistics of running a temple or grove.

It is also at this level that the Cleric approaches Name Level, and with it the zealous followers that form a High Priest's bodyguard; this in turn allows the Cleric, who ought to be spending treasure on upgrading and expanding his shrine into a full temple complex all this time, to fortify that temple complex into a stronghold in its own right. (See the Player's Handbook, p. 20.)

Wearing The Miter

Name Level means, with some additional struggle, coming into the power to create items. For the Cleric, that struggle is the erection and defense of his fortified temple stronghold and making 11th level. For the Druid, this is fighting his way up to Archdruid.

Either way, in addition to becoming able to create class-specific items, they also become authorities in their religions and in the world. This cannot be avoided. All of the friends they made on the way, all the enemies that still exist, their proud superiors and their adoring supporters all look to them to do great things in the name of their god and their way of life.

If the Magic-User and the Illusionist become noticed by cosmic beings at this point due to raw potency, Clerics and Druids do so because their service has brought them direct notice by their divine patrons (who grant 6th and 7th level spells). They can be, and inevitably shall be, called upon by those patrons directly to do as commanded. In addition all sorts of worldly patrons shall call upon them to request, demand, or otherwise seek some service or another from them- sometimes with a return offered, sometimes not.

In short, putting on the miter means that you're the boss and you're expected to act like it- just like if you were the Fighter turned warlord- only you're going to be dealing with supernatural affairs far more often than the Fighter.

It is also at this point that any territorial conflict between Druid and Cleric will become apparent, and that conflict will require resolution sooner or later due to both parties serving powers that cannot abide restriction on their reach or authority- and that conflict will compel others to either pick a side or get out of dodge.

Conclusion

The Cleric and Druid have as organic and inherent a career path as the other classes in the game. The only downside is that players and Referees may not understand what a religion is, and therefore how it works, in order to make such characters feel authentic in play; they are the inverse of Magic-Users and Illusionists, in that they serve supernatural ends by intervening in the ordinary world.

This dynamic will also be present for any other subclass of the Cleric, and you'll feel this pull in other classes that blend religious aspects into them (Paladin, Ranger, Bard, and sometimes Assassin). They represent the power and authority of something greater than the mortal world, and when they reach high level that status cannot be denied- and as such high-level play cannot avoid divine affairs in the world.

And that's before there are outright crusades between warring gods played out in the campaign.

It's easy to do the substance of these classes wrong; it helps to go beyond Appendix N in this case and do some historical or academic reading, or have someone on hand that has. I linked to a primer on the matter above; go read it and read further from there. You are more than a healbot that either makes dead things go away or turns into a cat.