Contrary to popular belief, comebacks in Dota2 are much more common than in LoL. Teams with a 10% gold lead 12 minutes into the game (generally about when the laning phase ends):
The main reason for this is that more expensive items in LoL are MORE cost-efficient than cheaper items, while more expensive items in Dota2 (while often having powerful effects) are less cost-efficient. So by buying these cheaper items, you can finish them sooner and have an advantage over your opponents who are building (and have hopefully not yet completed) higher tier items.
As a team who has lost the early game, you need to recognize this and attempt to get back into the game by purchasing mid-tier items of this sort. Some good examples are Bracers, Drums, Urn, and Mekanism. Carry items in this vein are Diffusal Blade and Maelstrom. For example, two Bracers cost 1050 gold and give 12 STR, 6 AGI, 6 INT, and 6 Damage. An Ogre Club costs 1000 gold and only gives 10 STR (with the advantage that it builds into excellent lategame items like BKB).
While you won't have the item-effiency (per slot) if the game goes on for a while, your goal as a team is to make that disadvantage irrelevant by forcing fights. You will have a period of time where you have equal or greater item effectiveness than your opponents who are presumably saving for more expensive items, and that is your chance to bring the game back into your team's control.
At the beginning of every game you should take a look at the hero lineups and figure out who has the superior lategame team. If you have the advantage in lategame and aren't incredibly far behind, it's usually advisable to simply farm and defend towers at all costs to prolong the midgame. However, if you are incredibly far behind or have equal or worse lategame (usually the case), then you should focus on ganking- better equipped heroes will farm faster than you.
Your best option is usually smoke-ganking as a team. You can catch an opponent or two out of position, kill them, and take an easy tower, Roshan, or teamfight with your newfound hero advantage. Just a couple of these occurances can often completely turn the tide of the game as you force opponents to take teamfights that they aren't properly prepared for. After winning these fights, you can place offensive wards, counter your opponents' warding attempts, and continue to lock your opponents into their base and assert map control.
Good luck!
Playing carry is truly difficult when it comes to decision making. I play carry in my party most of the time (being the most experienced player) so I can give you some advice and simple rules to follow.
General lane behaviour in early game
If you are good at last hitting, maintain the creep equilibrium close to your tower but not in tower range. Ask your support to zone the enemy out so you won't get denied. That's the first step of not losing XP in lane.
Farming > killing. Don't ever waste time chasing or ganking or rotating lane as a carry. You only want to farm as much as possible. Take a kill when its effortless and won't make you lose more than 1 creepwave. In term of gold 5 last hit is ~200+ gold (same as a kill). If the enemy offlaner is running away with low health, just let him go, he's wasting time, not earning gold or xp which is fine enough for you.
Early teamfight are not your responsibility but your mid's one. Except if the fight happens in the safelane where you should be farming, never TP to a teamfight. Few carries can teamfight early on anyway (Maybe Gyro or nai'x can bring something to the table). But usually, a carry's skill set doesn't allow him to fight early. It's also your teams responsibility to not take early bad fight.
Depending on the difficulty of your lane, ask your support to rotate in the jungle (stack and pull neutrals) or gank the other lane. If you can handle the enemy offlaner alone and if your support leave, you will earn way more xp by being alone in the lane (they just have to ward the nearby jungle so you don't get ganked easily).
If you are having a hard time (versus a trilane or an very aggressive dual lane) consider rotating lanes, going to the jungle or run a defensive trilane.
Don't build a midas unless you have free farm. And remember : since the 6.79 using the midas on the jungle is not worth it if you lose more than 2 creeps in lane so be carefull when you use it.
The mid game
In the midgame, your mid player should start rotating and creating you more space. Allowing you to farm more
Profit of the early mid game (10/15 min into the game) to take down the enemy offlane 1st tower.If you can jungle (lifesteal, battlefury, maelstrom), you have now a safer jungle where you can farm creeps easily, letting the lane for your support to get some gold. Defend your safelane tower only when creeps come too close and go back in the jungle
You can start showing to teamfight, let people get focused first then jump in and kill the easy targets (support, squishy heroes, low life heroes). If you win the fight take the tower and go back to farm > Repeat.
In teamfight
Never ever (ever) start a fight on your own, you let the initiator (clockwerk, earthshaker, magnus, tide, whatever) do his job then you jump in. Unless you are void, then you better hit that perfect chrono.
Don't focus the enemy carry unless you are sure to kill him. At some point you can take the support fairly quickly and win the fight by outnumbering them.
If the fight is lost : ditch and run for your life. You are the most important hero on the team if you want to win so don't throw your life in a lost fight. It's the responsibility of your team to not take bad fights but its yours to not follow them in a lost battle (in this scenario communicating is the key).
If you are always getting focused : build a bkb. Low level player tend to want to farm their big damage items on carry (like crits, MKB, Mantastyle etc.) but those item are useless if you die within seconds. In those situation recognize that you need a BKB and build it.
Some tips to have in mind
- If you are last hitting correctly and not being contested, you should have about 60cs (= creepstats = last hits) by 10 min.
- If you are a squishy hero (luna, AM etc.) : get strength power treads before rushing a big item, it can save your life more than you think.
- If you build treads, put them on strength, you will gain more survivability. Gaining 8 damage and 8 Attack speed is not worth the risk of getting bursted down.
- Also a magic wand provide some minor stats and a great way to heal if you get ganked. It will save your life more time than you can imagine so just get one.
Best Answer
First and foremost, always try to be aware of the times that you're not getting exp. You need to be within 1300 range of a dying creep to get the experience, which is about the same distance as a pudge hook or a blink dagger range. Play a few games with the sole target of getting as much exp as possible, so not wandering between lanes too much - use scrolls, and make the most of every creep wave.
If you're playing mid - make sure that you push the wave into the enemy tower before looking for runes, this forces the enemy to defend or lose 3-4 creeps of exp while you have time to pick up a rune without losing any. If you check for a rune (or worse, go back to base) and are missing exp on the mid lane you're putting yourself in a huge disadvantage. On those level based heroes it is critical that you get as much exp as possible. Learn to mind game your opponent in terms of last hitting, to put them off when they try to deny (or better harass them off the lane).
If you're playing a safe lane supportive role, make sure that any creep pulls you do are double stacks, or pull throughs to a 2nd camp - not just single stacks. Single stacks cause the lanes to push to the enemy tower, meaning you have to hang further back from the creep wave to not risk your life, and this makes it much easier for the enemy to zone you out of the experience range.
Always carry a tp scroll from as early as possible - teleporting between lanes rather than walking is 100% worth it if you are missing out on a lot of XP. Ideally, teleport in when the enemy tries to gank one of your lanes, and use your burst damage potential to turn the ganks around - this will give you huge boosts in xp.
Also needless to say, avoid deaths as much as possible. Learn all the best ward spots and keep as good map coverage. The best way to not get ganked is to not be there - and ideally make your enemy waste time rotating between lanes as well.
Hope these general comments are of some use to you, if you want to post a replay ID or two, I'd be happy to give more specific advice. Cheers.