In Dying Light there are two things stopping the infected from devouring Crane: the ingenuity of the remaining survivors and your skills. Without those skills, you might as well just lay down and let the virus take you, like many of the survivors do. 

This isn't an exploit guide - you can easily level up through a third party application (possibly facing online bans and unbalancing online play), possibly save file editing, or some crazy glitch discovered online, but that's no fun. This is the old fashion here are the options for you to level up as quickly as possible. 

There is so much possibility in the game that these tips are from my own personal experience, you may find quicker ways or not even want to level quickly. You will take a lot of the charm away from the game once the grappling hook is unlocked early on. 

Leveling Everything Fast 

Survive the night and you'll get a huge bonus XP. Night is about 7 real life minutes and you'll have to do it outside of a safe zone as far as I am to understand (I've never waited a night out in a safe zone). If you want to level up fast, just outside at night and either run (early on) or fight (later on). 

You can also go farm up overpowered weapons at the start like EXPcaliber and just grind at night, that's going to be probably the most fruitful option. Run and jump on things, grab airdrops, and fight volatiles. Starting out, especially with few skills, and not a lot of access to high end weapons, you may just want to play with some of the safer options below. 

Survivor XP 

Survivor XP is leveled from doing missions, turning in airdrops / quarantine supplies, killing bolters, and some other miscellaneous points in the game. The fastest way, beyond just farming airdrops and doing the quarantine zones (which are absolute huge amounts of XP) is to farm bolters at night near a safe house. There is a bolter spawn in the slums that's super close to a safe zone on the south border. Sleep until night, rush out and take out the bolter, then rush back into the safe zone which is going to grant you survivor and power XP. Sleep until morning then night again and rinse/repeat.

This is the most important branch because it determines the level of items that drop in the world and what is sold in the stores. You should always heavily focus on leveling up survivor XP as often as you can and get as many air drops as you can, when you are capable of doing so. 

If combat isn't your cup of tea, then just grind airdrops and side missions. You'll level up your survivor XP super fast that way. Survivor XP isn't doubled at night, but Power and Agility are, so don't stress about turning in missions at night. 

Agility XP 

Agility is leveled up through running at night (escaping volatiles) and climbing on anything. Two ways to do this, find a good spot where you can jump up on something, fall down, and jump back up. You get about 5 each time you grab something. Just keep jumping up and back down or, if you want to do something more engaging, climb one of the many towers. You'll have something to do and you'll get the trophy at the top. 

The night option is just to go running at night. You get a lot of bonus XP from agility. Agility is sort of leveled up very passively as you play through the game, so it's a bit harder to grind, but you'll often be grinding it along with everything else you're doing in the game. 

Power XP 

Fighting zombies is the way to do it, the trick here is to focus on survivor until you get camouflage, then go out either at night or even at day and take out a lone biter. Then switch on the camouflage (you camouflage from the fallen zombie) and then just go around and keep killing, non-stop, without remorse. Nothing will fight you and you can continue to re-camouflage every 20 seconds or so to keep anything from tracking you. 

Now, for the night option, you can easily just take a high damage weapon (700+) and stand around outside a safe house fighting volatiles all night. If you survive the night you'll get a huge bonus, plus the bonus each time you clear everything around you (because you successfully escape right). 

Kill Frenzy can help with farming at night, as you gain bonus XP.  

That's my ways to level quickly. What are your ways? Let us know in the comments below and share your tips with everyone.