A set of tips on how to play off role
Yes you could always dodge, but what if you have already dodged today once or even twice and the game goes through. It might not seem that necessary for most but I see tons of off role players that throw games out the window for their teams and I want to just give some pointers for when you find yourself in this sticky situation.
1.)Accept you will probably not be of much impact. You aren't playing a role you normally do and as such you shouldn't be acting in such a way. NO MATTER WHAT ROLE YOU ARE IN!
1.5) LET THEM ALL KNOW YOU ARE OFF ROLE They should know so that in most cases where nobody wants to swap they will know what they should be expecting from you. It really helps with stopping tilt.
2.) Try and pick a champion you know or that can span multiple roles that you know. This might seem obvious but this is how we got things like poppy, trundle, mf support, and things like trist and vayne jungle. High level players forced into off role or match ups that were extremely undesirable and wanted that win so they chose at least one thing that is comfortable to them. Don't however pick something that has no use in that lane. For example poppy has a dash stop and CC allowing her to peel support. A talon does not have that.
3.) Passivity comes before farming. Farming comes before fighting. Lets be honest you are going to blow at farming if you are using a champion you don't really know in a role you obviously can't work like everyone in your game can. You should be focusing on having the raw stats of levels and items cover up your deficiency and this also prevents your opponent from getting that bigger leg up on you. This isn't perfect and because of your naivete in the lane/jungle they might pull some huge play you never saw coming. Those are okay, but learn from them on just how passive you should be.
4.) Follow team mates Don't completely ignore farming, but know when to follow that team mate that is going to carry your sorry butt. Maybe you are like me and suck at ADC but if your top lane is stomping, rotate! Try to push their advantage instead of trying to get your own. This teammate might be a support that really knows what they are doing and roaming top to try and save your lane, or a jungler ganking right after red buff to try and start your lane off right. Just follow their calls and be ready to do what you are asked/told.
4.5) Look juicy enough to have stuff wasted on you. Maybe the right call here is to act like a distraction and let the rest of your team push. Just because you die in one hit doesn't mean your death has to be a gain for the enemy. Winning strats aren't always about gaining map pressure, sometimes its making the enemy opt to lose map pressure because of a overextended champion they chase down. The more time you have the enemy waste is the less time you are being a waste.
5.) Builds don't mean squat if you cant use them right. You aren't going to be the best, and if playing mid or adc you can be so squishy you wont do any damage no matter how many IE you have. Sometimes choosing that warmogs armor instead of that duskblade will let you survive just long enough to auto twice or let you heal back up because you position worse than a squirrel near a road. Choosing a healthier and safer build is better than copying doublelift or faker senpai.
6.) Accept reality. Don't be the reason your team loses, but realize when the game is over. Don't get angry or upset and realize your team did their best to try and carry you. Who knows you might actually be able to do something by following up on that 12/1 pantheon by 15, maybe your entire team will go 0/20 with you having a score of 0/1/0. The reason is even though you were disadvantaged you did actually try and didn't act as a hindrance to your team. Most would rather have an 0/0/0 off role adc than a 0/9/2 adc main who thinks they are the next gosu.
7.) accept at least one person on the enemy team knows you are off role. Op.gg lolwiz you name it there are resources to show how inexperienced you are. They might look to tilt you into oblivion, accept that and look at the other tips.