League-of-legends – When should I chose to upgrade to the Greater Vision Totem

You never stop to try and last hit the minions, except when you're playing support; then you'll leave the last hitting to the carry you are with. But at times it's good to push minion waves to the enemy tower (either using your spells or starting to auto attack), since enemy towers can and will deny gold (and XP - only when your opponent isn't there) from your opponent. But you always have to look at the map when you are going to push, because overextending and dying to a gank is worse then letting your lane opponent farm.

Conversely, if the enemy is pushing his minions closer to your tower, you can start auto attacking the minions to get them down faster, but even while auto attacking you still need to watch minion hp so you can get the last hit.

While this list doesn't cover every situation, it should give you a good idea of waht to keep in mind when looking to fight. I’ll cover the two most common times teams are looking to pick fights:

Laning Phase

During laning phase you have to be aware of a few variables before determining if you can go all in:

• Which damage dealer (for bot lane the AD carry, for the other lanes your (usually) solo opponent) went to buy last? Don’t try to pick a fight if the Graves just shopped and now has two more Doran’s blades over what your AD carry has. This also applies to the enemy team having more money from global gold (dragon, towers) or earlier kills. Be aware of who has the better items.

• Where are the junglers? If your jungler is waiting in the river bush and you just saw their jungle on the opposite side of the map then it is much safer to try to engage your opponent. Though, this often comes down to where are your opponents in lane.

• Is there a huge enemy minion wave? Minions add a lot of damage during the early laning phases and by attacking an enemy champion you pull all of that agro. This extra damage can easily sway a fight one way or the other.

• Who has their summoner spells? If the enemy looks low but is staying in lane still make sure that he isn’t baiting with summoner heal. Keep in mind that you can use this to your advantage. Ignite reduces heal effects so if you can ignite before they use heal then they are suddenly in a much weaker position. Also note when the enemy uses their offensive summoners exhaust/ignite so you can time your own attacks.

• Did one of the laners just go buy? If the AD carry has just left to buy and the support is throwing bananas in lane, then it is much safer to attack (assuming you are the AD carry or you have two people in lane vs. one)

• Where are they in lane? It is much safer to attack enemies that are pushed under your tower. If they attack you they take the massive tower damage and are much more likely to be ganked by your jungler. This is a good time to ping to notify you want to fight so your jungler can show up.

Team Fights

• Who has more people? Be aware of where your team is, if the AD carry is off farming top and the whole enemy team is arrayed across mid, then you don’t want to engage. If their AP just went back to finish that Rabadon’s deathcap then you have a window to engage (just remember the teleport summoner spell and that the shop isn’t THAT far away).

• Who is winning? Who came out of the lanes stronger, did your solo top go 6/0/1 and destroy their tower within 15 minutes? Then you have a big advantage assuming the other lanes went equal. However, if the enemy has knocked down 4 of your towers and gotten every dragon, then only try to fight when you have other odds in your favor due to the gold difference.

• Does anyone have baron? Baron can easily sway fights, if you have it then be a lot more aggressive. If they have it then try to only engage under tower. Did someone just get out of position? Sometimes you can win a fight before it even gets started by punishing someone for bad positioning. In these cases it is best to target the AD or AP carries, that removes a huge amount of damage from the enemy team.

• Is there an objective up? Sometimes it is more beneficial to group up around baron or dragon and force the enemy team to come to you or lose it. This allows you to control the field of battle (this is a great time to have all the wards cleared with an oracle).

• Are they doing a risky baron? Attacking an enemy team during Baron (assuming near equal strength) adds Baron’s DPS to your teams. This can often sway fights, not to mention the fact that sometimes the enemy team will split their damage between baron and the attacking team.

• Who has their ultimates/summoners? If you know the enemy Kennen has his ultimate, then it probably isn’t a good idea to group up in a nice tight ball (unless you have Janna who has her ultimate). Use the green dots besides your ally’s portraits to know when their ultimates are up. It is much easier to win a fight when you have 5 ultimates leading the way.

• Will fighting make you lose an inhibitor or nexus tower? If you have multiple inhibitors down then it can cause you to lose the game to engage an enemy team outside of your base. Make sure there aren't super minions pounding away on anything important.

Of course, it mostly comes down to experience. Sometimes you will want to engage a 3 v. 5 because you know you have some super advantage. Maybe the enemy is low from completing baron or maybe you know the Mordekaiser is just insanely fed.

Last note, be aware of the good initiator and counter initiators. Janna can easily reset a fight that goes badly. Blitzcrank and Nautilus can end a fight before it even gets started. Kennen, Ammumu, and Morgana can all punish a team for bad positioning and win it for their team early.