Starcraft

This is just one way to do fast exp in TvZ match up and maybe if I happen to get bored enought in future ill write about those too.

I wont put scvs nor suply amounts here so just produce scvs all the time
and when you got spare money build listed buildings. I also wont put every marine that you will be building, make those nonstop too. I will mention if theres reason to skip them.

suply
barracks
barracks (you dont have to hurry with this it doesnt make any diffrence if this comes minute later.)
1 marine (dont make more marines before expanding.)
suply
expansion inside your base, float it to your natural when its ready.

at this point it depends on your scouting what to do next:
if you see him making 6 lings:
make marines and send 2 scvs to ramp
gas
academy
suply (stop making marines untill gas aca and suply are ready)

If he doesnt make more than two lings dont make more marines before
gas
academy
suply

Now there are many options again depending on your scouting. (and if you are unable to keep your scout alive this long fast expansion might not be the best strategy for you)

1) you see him making 3 hatch before tech
2) you see him making 2 hacth and tech

1) make nonstop marines and build ebay for upgrade. After this you can still do many things.
If you suspect muta (also use scanner to find out his tech) make 4 barracks before teching more. You can also add second ebay before making more barracks and then make 4 rax to get fast upgrades. With 4rax you can be aggressive early on and delay his expansions. Dont forget to def you natural and exp with turrets and bunker too. Anyways you can also do factory after 2 or 3 rax too even if its vs muta, 4rax is just something Ive found to be quite effective.

If you think hes going lurks you can build still build 4 rax, in which case you can contain him and prevent expansion for some time. He will be able to push your army slowly towards your own base and he wil reach your natural before your tanks are ready so have a few bunks too to def against lurks. Note that 4 rax style takes strong micro against lurks as one mistake can easyly cost you whole game. WHen you get fac done you can go massive tanks with 2 fac, vessel tank, or SKterran with 2 port vessel. If he has hydralurk make 2 fac, if his teching quick make either 2 port vessel on vessel tank (one port and one fac). However 4 rax is not good idea on maps where is a cliff because it takes one lurk on cliff to kill expansion if you lack in tanks. Anyways there are many ways to play against lurk and allmost every pro has a bit diffrent timing for their tech. You can build factory (or two) earlier like after 2 rax in which case youll just have to sit in our base and wait to get tanks and vessel before breaking throught his contain.

2) note that in option 1 you can do the same as in option 2 and vice versa too but id prefer a bit earlier tech vs 2 hatch because many zergs go fast lurk dropping. I usually do:
factory (skip a few marines and dont upgrade stimpacks right away)
ebay +1 weapons (if theres a cliff over natural lift this there)
stimpack after this.
add on for fac
if he makes muta you are in slight problems. Dont make tanks but turrets and marines. Upgrade range for marines. Countering massive muta can be very difficult with this build but if you dont make mistakes with micro you should survive.
If he makes lurks get tanks soon and upgrade siege. Send 1st siegetank to natural and put it to cover cliff. 2nd sige tank to main base. Build bunker there and fill it with marines. Siege tank near bunker. This comes just in time to save you if he makes fast lurk drops. After this keep making marines and tanks. Tech to vessels when you have minerals.

Zergs can counter fast exp this with many ways. Most devastating are:
1) lurks drops
2) fast tech to guards/swarm
3) early ling
lurks drops counter is explained above.
For fast tech: make 2 port vessel and marines. If he has done mutas in beginnig chances are that you see guardians in which case you can make 3 port wraiths. If he does deflivers just keep pumping vessels and tanks and attack his expansions. When countering deflivers its importnant that you dont let him to put swarm right to your expansion instead you should force him to slowly push with swarmed lurk while you irradiate deflivers.
If you see a lot of lings with scout be careful as he might do early rush with them. Make bunker if you feel unsecure.
If you have built academy in time he will have 12+ lings against 2bats 2 medics and 6 marines. Keep your units close to your ramp because he cant do much damage unless he gets to your main.