I've been laying Dungeon Raid lately on my iPad Mini. It's a purely skill-based gear-based game. Er. Yes, that's what I just said.
Collect coins to buy gear, collect shields to upgrade gear, kill skulls to get XP to gain stats and up to four spells. Based on turns, skulls get stronger, hitting harder and taking more damage to kill. Pretty soon special ones show up which do all manner of terrible things like stop spell cooldowns from resetting or break the shield and sword tiles. And they have even more health than normal skulls, so they tend to stick around.
There are a many unique strategies to try: high damage, lots of healing, spells to stop enemy attacks. These aren't just turn by turn tactical choices, but over the long term they will matter.
Usually I go with a lot of Oh Shit buttons, teleport to reset the board with no skull, disarm to convert normal skulls into swords, and a couple of the "you can't hurt me this turn" spells. These were great, if I could survive between cooldowns.
More recently I picked a different tactic: overgearing. I got a spell to convert coins to swords, another to convert swords to shields, and to complete it, one to double my shields collected that turn. Collecting more at once increases the chances of getting bonus shields/xp/coins/potions, so clearing an entire screen of mostly shields was a massive upgrade. Possible upgrades include higher chances of bonus shields (or other tiles), more defense from shields, and more upgrade progress from shields. See where this goes? Yes, exponential. By the time I was done collecting even only half a screen of shields could trigger a half-dozen upgrades.
Eventually I became convinced that I was invincible. I hadn't only been upgrading my shields. I had increased the effectiveness of a single potion by 50 times (along with higher bonus chances), my base damage by over 100 times, and my defense was so high that my health barely ever got hit. I stopped needing swords (they give a damage bonus when matched) because my base damage would one-shot normal skulls. For a very long time I was untouchable, rolling in upgrades, spending more time picking upgrades to gear and my character stats than I was actually matching tiles.
It was gear inflation to a ridiculous extreme.
But I lived in mortal fear of the one skull that could hurt me: Spiky. Any damage I did to him, he did right back. Considering my base damage was something like 250 and my health was around 1000, yea, doing a quarter of my health back to myself was not appealing. They have a few hundred health, so to actually kill one would be a major hit to my own health. To make it worse, to hit other skulls as well I'd need to use swords to chain out to them, meaning even more damage, since excess damage still counts. So I had to leave it alone, dealing with the constant damage while keeping the other skulls away, hoping to someday deal with it.
Eventually I had a few special skulls out and my weakness was revealed: I had no abilities to reset the board. No teleport, no freeze, no exploding potions. If my damage could not get rid of my enemies, I was in trouble. So eventually I found myself with a board devoid of potions, at low health, and hoping that my health leech effect would do the trick. It didn't. I tried one last gambit, grabbing a few potions, hoping for a cooldown to come up, a new line of potions to appear, and indeed I got healed for a lot. But wow did I get hit by even more.
And so I died. Neither gear nor skill can save you from the inevitability of the random number generator. It might take a long time to catch up with an exponential growth, but chaos has time to spare.