"First Hassan"

There is no summon trick to this game dude. Just roll and hope for the best, you can try anything as a summon ritual. However, if it fails don't get all discouraged.

Become one of the HaZZan's "big family" and do wrong things, so he definitely will come in order to aZZrael your butt.

Kill someone. Doesn't matter who.
Death is the catalysator to summon him.

Jokes aside, it's the same as with all other summonings.
When I was rolling for him, I tried a few single pulls at first and got some rather good CEs like Black Grail.
So I thought my luck is on a high level at the moment and did a 10-Pull in which he answered my summonings.

Maybe you can try that as well.

There's one surefire trick to getting him; you whale, and whale hard. Otherwise, there's really no helping things. You're just out of luck if you don't get him. My advice? Just look at the list of Servants and their release order and start saving up and planning ahead for the next 2 years. Some Servants are more likely to come out more for random banners, so prioritize the rarer ones. I'm personally not going to spend any SQ until the Sakura clones are out. That and this year's Summer Servants are my main targets for this year.

I guess it's easier to wait when you've got a reliable stable of Servants and friend supports. I know I was rather impatient on these random banners since I sorely needed stronger Servants I could rely on to be the core of my team, and I finally managed to settle on a reliable collection of them at last. Now I'm just going to be raising the ones I neglected (like Jeanne) until the banners for the Servants I want to get arrive.

Offered 44000 FP and summoned him at midnight, he came at the first ticket.

How much did you spend? If you only have 30 left you should try solo rolls, i usually get my SSRs there.

Was in the same situation, rolled in despair, and the last card turned out to be him. Have hope, and good luck!

And worry not if you don't get Gramps, Jack the Ripper is his contender as the best Assassin in the game, and she gets many rate-ups this year (the first one being in April). There should be another King Hassan summoning campaign in November this year, so if you want him so badly, you can try again then. Just make sure to plan ahead of time which servants you want the most this year in order to have a good amount of SQs for Gramps.

try to dont catch up by desire cencor

Maybe try to have all 3 Hassan of the old man mountain servants present in your party?

When I summon him I had Cursed Arm, Serenity, and Hundred Persona in chaldea and each of their NP was above lv 2. Since he came in my first summon it was as if Cursed Arm, Serenity, and Hundred Persona played a role in summoning him to complete the current Hassan Family.

Maybe First Hassan will answer your summon by establishing all 3 Old man Mountains.

This trick might boost your spirit (and luck): Listen to Assassin's Creed Main Theme mashup while you're rolling, I just did a yolo roll on him yesterday and Gramps answered my call :3 (along with a NP2 loli snek).