A lot of NBA players believe the power of the mind starts with the soles of the feet. Draymond Green is among them. That's why, when third-string center Kevon Looney prepared to face the Rockets in Houston midway through the 2017-18 season after not seeing the floor the previous two games, Green summoned equipment manager Eric Housen to replace the shoes sitting in front of Looney's locker. Housen is in charge of laying out each player's gear in their locker before the game. On the road, that includes their shoes.

When Looney arrived to get ready for the contest, he noticed something was missing. "Where are my shoes at?" he asked.

"Draymond says you can't wear them," Housen said. "They're James Harden's shoe, and he says you can't wear the shoe of a guy you're playing against."

Looney didn't have a problem with the rule—just Green's shoe knowledge.

"Wait a minute. They aren't even Harden's shoe!" Looney complained. "So can I have them back?"

The shoes were returned, but he has adhered to the policy since. As an Adidas-sponsored player, he rotates between wearing Harden's signature shoe and that of the Portland Trail Blazers' Damian Lillard, but he doesn't wear their shoe when he's on the floor with them.

Signature shoes, as it turns out, are an ecosystem unto themselves, influenced by everything from rivalries to team power structures to financial subsidies. It's Game of Thrones played out in podiatry fashion at floor level. 

And LeBron James, as with so many NBA-centric subjects, is at the heart of it all. No player has inspired more opponents who once swore by his signature shoe to vow never to wear them again. Green not only stopped wearing his LeBron Soldiers after he faced their namesake in the 2015 NBA Finals, but he also began inspecting his teammates' gear before games. If he caught someone preparing to wear the signature shoe of any Warriors opponent on a given night, he'd have Housen take them, as he did with Looney last season.

Some slip through. Warriors forward Jordan Bell was not aware of the rule and got away with wearing Paul George's signature shoe in this year's season opener against the Thunder, although he saw less than seven minutes of action. Then again, after he broke his foot in college, Bell has had to choose his shoes based on fit and comfort more than allegiance.

"My foot is really sensitive about what shoes I wear, so I don't have that luxury," he says. "I broke the fifth metatarsal on my right foot. Had a screw put in it. Had two surgeries. I wore KDs until last year and then my foot just didn't like 'em. I felt a burning sensation. The most comfortable shoe for my foot are PGs—high ankle support, nice cushion, not too thin, not too thick, still light but has that comfort you need."

Green is apparently willing to make allowances.

"It's not a team rule at all," he says. "We don't look that deep into it. I'm just not a fan. So if I see some guy doing it, I'll say something, like, 'Hey, for one game, put on a different shoe.' When we're playing against Houston, Loon is switching on James a lot. If you're out there playing against him in his shoe, he's got you dominated already. Early on in my career I used to wear LeBrons, and I was like, 'So? They're comfortable.' And then as I started to grow and I'm into my second and third year and I'm like, I'm battling with this dude. I can't wear these shoes anymore when I'm going up against him."

The Cavaliers developed the same policy regarding Steph Curry and his Under Armour signature shoe. It was understood more than plainly stated, leaving one member of the Cavs' Finals roster last year unaware of the rule—but only, perhaps, because he never considered wearing UAs. Another former Cavalier texted: "There was no way anyone on [Cleveland] the last few years would wear [them], for the obvious reasons."

A former NBA journeyman said several of his teams had top stars who tried to implement anti-Kobe and anti-LeBron shoe policies. "It's ego stuff," he said. "I still wore what I wanted."

Toronto Raptors guard Danny Green has experienced the shoe hierarchy's full spectrum. Or at least nearly. He started his career as a second-round pick with the Cavaliers and LeBron as a teammate. When James offered to supply him with Soldiers, Green happily took him up on it and continued to wear them even after he joined the San Antonio Spurs a year later. Then Green and the Spurs were upended by James and the Miami Heat in the 2013 Finals.

"I gave them up soon after that," he says. The bitter taste of losing to James after being 19.4 seconds away from a clinching victory in Game 6 inspired him to switch to signature shoes by George and Kyrie Irving, though he made sure not to wear their shoes when he played against them. It required a bit of foresight—checking the schedule to see when he might be playing against someone with a signature shoe he liked and having alternate shoes packed.

"You know what your road trip looks like and who you're playing," Green says. "No road trip is usually longer than three or four games. So I'd think, All right, we're playing LeBron, we're playing KD, we're playing OKC. I'll bring some PGs until we play OKC, and then I'll wear some Kyries or something like that."

He made an exception only once. The last time he played against Kobe Bryant, he wore provided black-and-gold Kobe Tribute shoes. Until halftime. "Tried 'em," he says. "Too much like a soccer shoe. I gave 'em a half. Went back to my regular shoes."

He doesn't have to worry about any of that now, having signed with Puma—which does not make a signature shoe for any of its players.

Some stars are apparently more forceful than others when it comes to offering their shoe to less-fortunate teammates. Former Clippers center Ryan Hollins says he was practically coerced by former Clippers point guard Chris Paul into trading in his Kobes for Paul's Jordan Brand sneakers, which apparently took up the majority of the team equipment room.

"He told me he could hook me up, and I tried to play it off," Hollins recalls. "I was like, 'Ha, ha, no problem. You're joking right?' But Chris said, 'No, for real.' So I told him, 'I'm a Kobe guy because they feel good.'"

Paul wouldn't take no for an answer. "What size you wear? We'll have some 17s later in the week for you." Hollins tried them—hey, when you rely on the man's lobs for buckets, you obviously want to stay on his good side—but Hollins eventually went back to his Kobes, placating Paul by wearing the CP3s in practice.

The Warriors are unique in that they have three players with signature shoes—Curry, Kevin Durant (Nike) and Klay Thompson, who has a deal with the Chinese company Anta. Durant and Curry are happy to supply any interested teammate with their shoe, but they stop short of recruiting. Not so with Thompson—at least not when he saw teammate Jacob Evans, who had worn Curry's UA shoe in the Las Vegas Summer League, trying out Rajon Rondo's signature shoe with Anta at the start of this season.

"Klay walked into the locker room," Evans recalls, "and he was like, 'We can't give him the KTs? What's going on? I'm going to call 'em right now.' Klay definitely was on me to join the Anta family. He was just telling me about the company, and the gear, how the shoe felt, the perks in his deal and his trips to China.

"Once I started wearing his shoe in practice, he'd ask me all the time how they felt, if I liked them. He was just making sure I was happy. He made sure they were sending me enough gear and that if I needed more gear just to let him know and they'll get it done. Even though they are high-tops and I haven't been a high-top guy, they're some of the most comfortable high-tops I've ever played in."

There's another part of the equation that is easy to overlook: Stars with signature shoes also have nine-figure contracts, while end-of-the-bench players could find themselves suddenly waived and buying their own gear. It's all well and good for top-line guys to worry about mind games based around what's on their feet, but, as the former Cavalier also texted: "If the 12th guy is offered money and $20k in merch YOU ARE GOING TO WEAR THAT S--T."

Leave it to Nick "Swaggy P" Young, recently released by the Denver Nuggets, to take a completely different approach to signature-shoe warfare. When he knew he'd be facing Kobe or LeBron, he'd make a point of wearing a rare retro pair of their shoes, ones that would prompt a double-take from their namesake—and perhaps a momentary distraction. "He wore old LeBrons that maybe only LeBron would have," Looney recalls of his former teammate.

For Green, the choice to not wear a rival's shoes is not only about making a statement but also about making a pitch for his own shoe. His Nike Hyperdunks have his logo on the tongue, but Bell quickly clarified that they do not qualify as signature shoes. "There are no DGs," he says, laughing.

Not yet. Green isn't giving up hope.

"If you're always in another guy's signature shoe, how will a shoe company ever look for you to possibly get your own?" he says. "That's the real reason I stopped. I would've continued to wear LeBrons and just not worn them against him. But if I'm in another guy's shoe, they'll never look at me that way."

Ric Bucher covers the NBA for Bleacher Report. Follow him on Twitter: @RicBucher.