I see a lot of people talking about the idea of roles and if a cleric should hear or a fighter should fight. I know that 5e has less dependence on class role, but I always looked at classes as having roles and players mostly needing to play those roles. If I have 4 friends and one wants to play a fighter that is an archer. That just means that someone else needs to front-line fight. A cleric that refuses to heal would be just as bad in the group. Saving the in combat heal is ok to a point, but at some point the front-line fighter may feel like he needs to pull back and shoot since he is low on HP, leaving the others in the party to now be in the front line.
I am saying you are wrong.
You can play 5e without a front-line fighter. A fighter is
capable of being a front-line fighter. But, honestly, so is a rogue or a ranger or a wizard or a cleric or a bard.
Healing in combat is usually a bad plan. If enemies are so tough that you are at risk of dropping regularly, healing will slow down your death
worse than helping drop the foe who is doing damage.
If enemies deal 18 damage per swing, on average you go to 0 with about 8 HP left. A 4 point heal brings you back up to 4; you can now take 1 more swing. This heal is far, far more effective after you are at 0 than it was when you where at 8; at 8, it would do next to nothing, at 4 it soaked a full blow.
There are some efficient heals, like a light cleric casting mass cure wounds or healing word. A mass healing word on a 20 cha cleric is 12 HP to 6 allies and 5 HP to themselves, 77 HP healed for a bonus action and a 3rd level slot. A mass cure wounds is 25.5 HP to 6 allies and 7 to themselves, 160 HP healed for a bonus action and a 5th level slot. Their channel divinity is also a huge amount of HP healed, Paladin LoH used as a massive heal is decent (using it in smaller amounts is action-inefficient, but you do need to save some for an action-stand-up), order cleric leaking out a healing word most rounds for a few HP plus a free attack is good.
But a 16 wisdom cleric casting mass healing word is 33 total HP, half that of the optimized healbot above. (and mass healing word is a good heal spell!) A mass cure wounds, similarly, is 99 HP for a 5th level slot and an action. A cure wounds on one creature at 3rd level? 16.5 HP at the cost of an action and a 3rd level slot.
Actions are currency, spending them on healing is
expensive.
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I understand that a greatweapon fighter is more effective with a cleric burning spell slots on heals to keep them up.
But that same fighter with a cleric laying the smackdown on things as well is even more effective in 5e D&D.
And for in-between fight healing, rangers rival clerics at downtime healing in this game.