
Summoning, explained: why the option keeps going grey
"Summon" means two unrelated things in Elden Ring — Spirit Ashes and other players — and most "can't summon" problems come from mixing up which rules apply to which.

"Summon" means two unrelated things in Elden Ring — Spirit Ashes and other players — and most "can't summon" problems come from mixing up which rules apply to which.
Elden Ring uses the word "summon" for two systems that share almost nothing: Spirit Ashes call an AI-controlled ally out of an item, while co-op summoning brings in an actual second player. They have different requirements, different items, and different reasons for failing — most "why can't I summon" confusion comes from applying one system's rule to the other.
A Spirit Ash summons a fixed NPC-controlled fighter — a wolf, a knight, a swarm of jellyfish — for a limited encounter. To use one you need the Spirit Calling Bell, an item you pick up early in the game once you already have Torrent, and you have to be standing near a Rebirth Monument: a stone marker, present at most points of interest and nearly every boss arena, that shows a glowing gravestone icon on screen when you're close enough. No monument nearby, no summon — that's the single most common reason the option is greyed out for a Spirit Ash specifically.
Two more rules limit how often you can do it. You only get one Spirit Ash summon between rests at a Site of Grace — kill your spirit or run out of the encounter and you have to sit at Grace again before summoning another. And Spirit Ashes are unavailable the moment a real player is also present in your world through co-op, which is the opposite of how the other system works.
Bringing in an actual player is a separate item chain. Furlcalling Finger Remedy is a consumable that reveals other players' summon signs on the ground — gold signs are cooperators, red ones are hostile invaders — and you need it active before any sign becomes visible to you at all. You can buy it, craft it from two Erdleaf Flowers, or find it lying around, and it's cheap enough that running out shouldn't be the blocker it looks like.
To let other people summon you as a helper, you place your own sign with the Tarnished's Furled Finger, an item found near the very first Site of Grace in the Stranded Graveyard. Placing a new sign replaces whichever one you had down before. There's also an optional Multiplayer Password, set from the menu, that restricts who can match with you to people using the same password — useful for summoning a specific friend rather than a stranger.
Sort the failure by which system it's in:
Spirit Ashes level up independently of your character. Roderika, once she's settled in at Roundtable Hold, offers Spirit Tuning: hand her a summon and she strengthens it using Grave Gloveworts, a material found throughout catacombs and other corners of the Lands Between (rarer Ashes use a related item instead). The upgrade raises the summon's attack and defenses without touching anything else about it — same behavior, same moveset, just tougher. It's worth doing early, since a low-level Spirit Ash against a mid-game boss dies in seconds and stops being useful as a distraction.
None of this changes how or when you meet the NPCs who hand you these items in the first place — if you're still working out where to go at all, where to go first covers the opening stretch that gets you Torrent, and with it, the door to Spirit Ashes.