Let me preface this guide with quick disclaimer: This is not a tried and true, competitive build. This is a simple guide for the average player to help pick up a few of Thresh's nuances. If you're looking for the best way to get to diamond, look elsewhere.

Hello, welcome to "Thresh for the Average Player." Allow me to give you a little background as to who I am. I play mostly Summoner's Rift (5s/SR) and Twisted Treeline (3s/TT). My main champs're Anivia and Maokai, but aside from them, I almost exclusively play support (in fact, I can also play both of them as supports, as well).

Origin of Guide's Name Play Video

As an offensive tank support, Thresh focuses on building defensively, while playing aggressively. This is different from how, say, Braum plays. Instead of being a brick wall, stopping incoming damage, Thresh operates best when he can control the flow of a fight, going in with Death Sentence when he wants to, and disengaging safely, either by peeling or by simply being a distant, lantern-throwing machine ( Dark Passage= "lantern").

To reiterate, your main goal as Thresh is to set your marksman (and later, team) up for success. If you can safely harass with basic attacks, by all means, do so, but don't think that you need to deal damage to contribute. See how the players are moving in bot lane. If someone's being overconfident without doing something to back it up, punish them. Either go for hooks (hook= Death Sentence) to start a combo for you and your marksman, or follow up with him/her if s/he gets a particularly nice shot off, and gets the enemy into a bad position.

It's everyone's job to ward, but you're the president. You have the most responsibility, especially for the bottom half of the map during the laning phase. You have a minimum of three wards in your inventory once you get Sightstone, which is a core purchase, so keep on top of it. You have almost no excuse not to have at least one or two wards out at all times. Keep tribush and the bush to the bottom-right of the river warded at a minimum. Warding dragon is also extremely important, so keep an eye on it. It also isn't a bad idea to sweep (use Sweeping Lens on) the entry of the dragon pit when you walk by, to try to deny the other team vision.

As previously stated, your main stats are defensive. Despite the fact that you don't gain armor or MR per level, you're still an incredible tank. To help augment your weak base stats, though, you should take flat runes. Bottom lane in general takes flat runes, because early kills mean a lot down there. The only exception to your defensive mantra is the AD marks. They help with Flay's passive component, as well as making Relic Shield's Spoils of War easier to secure, which not only translates into more damage, but gives you more gold, and both you and your laning partner more HP.

Just to clarify, Thresh's basic attacks are ranged, and as such, do not execute minions. You must last hit like anyone else in order to use Spoils of War.

Acceptable Marks
Greater Mark of Attack Damage: Makes last hitting easier for Spoils of War, increases Flay's passive's damage.
Greater Mark of Armor: If you'd prefer, these're the best marks for tank supports, and would be a huge boost to your level 1 defenses.

Acceptable Seals
Greater Seal of Armor: The classic, ubiquitous seals. Useful on every champion.
Greater Seal of Health: These have become a preferable alternative to armor by many, but if you take AD marks, you don't have room for these. That being said, I would still use armor seals. 9 armor matters a lot more late game than 74.16 HP ( Juggernaut ).

Acceptable Glyphs
Greater Glyph of Magic Resist: The standard glyphs for bot lane in general.
Greater Glyph of Scaling Magic Resist: If you don't need the MR up front (or before level 9), these're actually the best glpyhs in the game. The only reasons that I don't take them on supports are because you gain exp very slowly, so you can't ramp them up fast enough, and also because in bot lane, you need early stats.

Acceptable Quints
Greater Quintessence of Armor: Prevent damage against marksmen, and later, the rest of their team, dragon, etc. This is also no small amount of armor. The quints alone give you more than a Cloth Armor.
Greater Quintessence of Magic Resist: If you need early MR (draft mode or something where you can see this), opt for these. Even though Thresh doesn't gain MR per level, I don't go for these, because Merc Treads are a possible early game solution for MR, as well as Aegis of the Legion. Also, it's extremely rare that the enemy marksman won't be dishing out a lot of physical damage.

This is gonna become a serious wall of text, as I outline what you do throughout an entire average game.

Relic Shield is the best starting item for Thresh, imo. It gives you the tankiness that you need, and it has relevant early game stats (unlike Ancient Coin). Most of the time, you don't need to worry about ganks too early, so I don't start with any wards aside from my trinket. Between the two trinket wards (you and your marksman), you can generally have enough vision to last until you get Sightstone. Fill the rest of your slots in with potions to help you during the start of the game.

Your main items should be Face of the Mountain, Sightstone, Sweeping Lens, and boots. Initially, you should go for Targon's Brace and Sightstone. From there, finish your core, then you can branch out. Boots are a relatively simple decision, especially since you have from the loading screen of the game to think about it. If the enemy team has a Fiddlesticks, Lux, Veigar, or someone else who has a lot of CC that Tenacity can reduce, always get Mercury's Treads ("Merc Treads"). Tenacity is a ubiquitous stat that people often overlook. Mobility Boots should be your go-to pair of boots if you don't need tenacity. They're dirt cheap, and they allow you to get back to lane faster, roam better, etc. Whatever your choice, finish Face of the Mountain afterwards.

At this point, you have everything that you need to be a support. Everything from this point onward is only to make your job easier. If you're ahead, and your team is in a good enough place to not need you to be unkillably tanky, you can get some damage-oriented items. Sunfire Aegis grants you some tank stats, while giving you an AoE, DPS, magic damage aura. Just by being near enemies, they take damage. It doesn't give you the kinds of stats that other items do, but it gives you an often underestimated amount of damage. Zz'Rot Portal is an amazing new addition for supports in general, but it really shines on support tanks. This gives you some much needed pushing power if you happen to be the only one fighting back a wave of otherwise unkillable super minions. Aside from that, you get awesome stats: 50 armor, 50 MR, 100% health regen, and the Point Runner passive. Turbo Chemtank bestows an outstanding team-wide, Ghost-like effect, but only for chasing, it doesn't work for escaping. For this reason, it's strictly an offensive item. That being said, the speed boost is enormous, and is the entire reason you'd buy this item.

Being able to fight is fun and all, but never forget your main function, a tank. Due to this fact, your main items are often the defensive picks. Frozen Heart gives you more armor than Randuin's Omen, as well as helping your entire team from AS-based champs with the awesome aura. It also gives you a ton of CDR, which allows you to hook, lantern, and Flay more often, as well the mana to solve any problems. Thresh isn't at all mana hungry, especially once you get to team fights, so if you're running out of mana after this, you're doing something wrong. Thornmail is another item that boasts huge amounts of armor, but it also has a very interesting passive. It helps your team by damaging anyone who attacks you, especially if you can make that person the enemy marksman. It helps you by offering a metric ton of armor. It's also fairly cheap. Locket of the Iron Solari is the support version of Spirit Visage or Banshee's Veil. It gives you very similar stats, albeit weaker, but the draw to it is the value to people aside from you. It may only give you 40 MR compared to Spirit Visage's 55, but it gives 20 of that MR to everyone teammate within a huge radius. It also gives them some health regen. Aegis of the Legion works best the earlier you get it, however, the actual locket isn't that strong until later on. The active is decent, because it can shield your entire team, but it isn't that huge on any single person. With this item, you'll also have three shields to give to allies, so that's fun. Dark Passage + Face of the Mountain's active + Locket of the Iron Solari's active shield = nearly half of a squishy's HP, so you can give them some serious defense.

Upgrades are vital to the late game, should the game last that long. Ruby Sightstone gives you more HP, boot enchantments improve mobility in some way, and elixirs give you more, flexible stats.

With offensive items, Thresh allows his team to push down lanes with little care enemy champions. With defensive items, you get tankier than most top laners, and can effectively control fights without fear of immediately dying.

I know that Ancient Coin is still a few Thresh players' support item of choice.
Stop it.

Ancient Coin is a bad item! I can't think of a champion who benefits from this more than Relic Shield or Spellthief's Edge. Ancient Coin gives the least gold, provides by far the least stats. The only redeeming qualities to the entire item line are the MS from Nomad's Medallion, and the active on Talisman of Ascension. For these two things, you're giving up any tank or damage stats (the two kinds of supports are mage and tank, so...). If you're using the Talisman active for escaping, you need tank stats/ Face of the Mountain's shield more, and if you're using it for offense, just get Turbo Chemtank. It's better at it in every way.

If you need mana regen early and are a mage, you should getting Spellthief's Edge for a bit of AP, the same amount of mana regen, and VASTLY increased gold income. If you're a mana hungry tank, deal with it. Cast fewer spells and get Frozen Heart or something with mana ASAP, because you can't afford to pass up the HP from Relic Shield for such a worthless amount of mana regen.

Thresh isn't mana hungry! At all! You don't care about mana regen whatsoever, and you're a tank! This isn't even a debate, Relic Shield is your only choice.

Thresh has a fairly diverse kit, and with it comes a slew of potential combos and maneuvers to make plays. Below, I'll detail a few of them, ranging from basic to more complex.

Basic
Death Sentence + Flay: This combo can be hard to get off sometimes because it requires that you land a raw hook, however, the strategy behind is fairly simple, and probably what you'd do on reaction if you landed a sweet hook. One thing to keep in mind is that you don't always need to go in with the Q to get Flay off. The range knockback/pull is static, meaning that no matter where you are in relation to your victim(s), they are pushed/pulled the same distance. The edge of Flay is the same as being on top of them when you cast it.
Anyway, the idea behind this is that you keep your target within range of your marksman/team for as long as possible. With the hard CC of both abilities, coupled with the lingering slow from Flay, it gives your allies ample time to land a few good hits.

Flay + Death Sentence: The reverse also works amazingly! The problem with this combo is that you need to be within Flay range to start it, but it's a lot easier to land the hook on a slowed target, so there's a definite give and take.

Intermediate
Dark Passage + Death Sentence + Flay
Death Sentence + Dark Passage + second Q + Flay
Both of these combos accomplish the same thing, just with varying degrees of effectiveness, if you get the jump on someone, or if it's more of a reactionary combo. This is the same as the above combos, but you pull someone else with you.

Death Sentence + The Box + Flay
Death Sentence + Flay + The Box
Your standard all in. You can also toss Dark Passage out to bring someone else in the box with you to get the dude. Usually, you won't have time to use your ult before Flay, but if you can do it, go for that, because then you can flay people into the walls, forcing them to take damage and the 99% slow.

Flash + Death Sentence + any of the previous combos starting with Q: Sometimes, your targets only have one point of escape, and you can throwing a leading hook to grab them at their only safe option. This isn't a free hook by any means, because it still has a long cast time, but sometimes distance is the only factor preventing you from catching someone, and Flash fixes that.

Dark Passage + Flash: This one might not jump out at you, but this can easily save someone's life. If you're next to a large but blinkable wall, throw your lantern out, wait for someone to click on it, then immediately Flash the wall. This pulls your friend to freedom on the other side of the wall.

Flash + Flay + any combo from Flay: This one requires a knowledge of spacing, because it doesn't give you a huge range boost. This is just for catching someone who's otherwise faster than you, and manage to stop them just in the nick time.

Advanced
Flash + The Box + Dark Passage + Flay + Death Sentence: If you're within Flashing range when you want to start a fight, you can do it, throw down The Box, pull someone in with you, then cripple an enemy.

During the first wave of minions, you should immediately try to kill the first melee minion to give both of you gold, and allow Spoils of War (SoW from here on) to begin charging. After this, try to focus on killing cannon minions for the most gold. If you're marksmen isn't gonna get the last hit on one and you have a stack of SoW, or if one of you needs the heal, go ahead and kill that minion. If you miss a cannon minion, go for a melee minion, as they give the next most gold. Caster minions give the least amount of gold, so don't both going for them in most situations. If you lose more than 200-250 HP, go ahead and use a potion. You have health regen, so let it be used, but you don't wanna be too low at any point. Don't heal everytime that you get hit, but don't overestimate your health regen.

Your first back should be with 500-1300 gold. Going back before this slows you down pretty dramatically (heal if you must, be smart), but staying any later allows your enemies time to get a substantial item advantage. Your core items are Targon's Brace and Sightstone, which cost a combined total of 1300. This is where this figure comes from.

When deciding what to buy, look at an external forces affecting your lane. If you're constantly being ganked, go for Sightstone first, but if things are relatively normal, I always get Targon's Brace before Sightstone, for the simple fact that Targon's gives you everything you want early game. Regen and increased gold income are both vastly more important at minute five than minute 35. You still have wards thanks to your trinket, but it isn't possible to increase your gold income without either, A. Stealing it from your marksman (terrible idea, don't even consider this), or B. Targon's Brace. The CD for gathering a charge of SoW is halved when you upgrade from Relic Shield, so do it ASAP.

Once you have Sightstone, start warding dragon, among other locations such as tribush. This accomplishes two things for you. First of all, it grants your team vision of dragon, and if your top laner has Teleport, s/he can join you, if need be. The second thing is a warning for you, mid lane, and your jungler (4/5 of your team) if someone is trying to gank and/or take your jungle. This ward is invaluable.

Soon after this point, team fighting'll begin. Laning becomes less rigid, and the focus shifts over to objectives and pushing lanes.

Thresh has three main roles that he can fill extremely well in team fights:

1. Initiator: Starting fights. If and when your team's in a good spot, Thresh has a variety of tools at his disposal to effectively start fights. Literally every ability and both summoner spells can be used to start fights, including Dark Passage. A well-placed Death Sentence or Flay can easily spell someone's death.
2. Defender: Peeling, blocking skill shots, and otherwise using defensive plays to keep your squishies safe. The simplest one being a hail mary lantern to pull your friend out of a fight while you're already safely in the back line. If people continue to chase your buddy, hook and Flay them away. The Box and Exhaust can also help with this.
3. Chaser:Don't let them escape. If someone else had a great initiation, combo off of it! Thresh's abilities can make it extremely difficult to escape from a nasty situation.