If there is absolutely NO WAY to contact the side of the unit that you're facing (remember even corner to corner counts as contact) then a declared charge will end up being a failed charge. You cannot end up in base contact on a facing you were not in at the beginning of the turn.
Some important things to consider:
pg 20: "You are free to make this wheel in order to place your unit wherever you like *against the facing of the enemy unit that is being charged*..." (emphasis mine)
pg 21: FLANK AND REAR CHARGES - the whole section really, but of note: "A charging unit's position when the charge is declared determines whether it charges into the front, flank, or rear of the enemy unit."
If you think about it: oftentimes when you're fighting in combat your flanks are open to being engaged, but an unengaged enemy unit that is in their front arc doesn't magically get to move into their flank to engage them in combat. You've got to re position into their flank to charge the flank. Same situation here I think just replace an enemy unit in combat with impassible terrain.
In the example given only one of the two chargers can make contact - and then can only do so by fudging the clip on the front corner of the receiver. I would allow it as there appears to be enough room to fudge it to make it work. But there isn't enough room for both to make contact on that front corner (or anywhere else)
I would argue that while one of the chargers could make contact, because neither side could "close the door" then it would be a failed charge. If it could be finagled where a close the door situation is possible then absolutely at least one unit could complete a charge there because of proximity to the edge of the terrain.
Honestly I would just say move both of those units around each side of the terrain and then next turn either get a double flank or front/rear charge.
I see your scenario and I raise you another scenario:
This scenario replaces impassible terrain with an enemy unit. Both units that want to charge are in the front arc of the green unit but can't, because there's no room in its front arc.
@ryryak yeah I agree and we did play it out with charges not allowed. But now when think more it might have been abel to do a corner to corner charges having one model in each unit fightning. But then comes next question. May I draw a closest line througn impassable terrain for the dice roll needed?
This was the situation but after I moved the green units as I dint charge with anyone of them as we were not sure. Big problem was they were bombarded by cannons so I wanted them in combat
@ryryak If you can clip a corner you have made contact. In the diagram you have presented there is no corner available to clip. Slide the red unit over either way until the lateralmost file's outer edge is even with the green unit's outer edge and you would have a comparable situation.
In the original diagram we were shown you would have to fudge the defending units position to allow the charge. 8th made this much more allowed then say 6th ed. Mind you it's close in the diagram to being possible/impossible. Would have to see it on the table.
From the actual game picture I can't really tell what's going on. . .
You would measure the straight line through the impassible terrain to determine your required charge roll. You can move infinite distance on the charge as long as you made the required roll and all other rules on wheels etc during a charge are met.
I understand that clipping a corner creates base contact. What I'm (trying to say) is that you can't just clip a corner and remain at an angle. You need to be lined up flush with the facing of the enemy unit you're charging, which is why I'm saying that charge may not have worked. I'll provide pictures:
Your red lines have determined that the enemy is in the front arc of your units. The pink arcs I drew show the facing that you will have to charge against the enemy unit.
This charge, while technically making contact is an invalid charge because you're not flush with the desired facing of the enemy unit; you can't "close the door" and so it's counted as a failed charge.
Unless the enemy can close the door (it's okay to come within 1" of the impassible terrain here as it's for combat) whilst avoiding the impassible terrain then the charge fails.
Also strutsagget your in-game image where you drew your lines looks like the skullcrushers were in the front arc of those scouts so there should have been no reason why they couldn't charge them.
I would have shoved the defender backwards to allow the charge possibly (a big fudge) but in terms of closing it's a "virtual close." We close the door by bringing more models into contact. In a clip there is only one model from each side in contact. The intention of the close is a free wheel to maximize models in contact not to force perfectly square line ups. For example many people base their warmachines on rounds or don't base them at all.
You can't (no matter how you try) get to a square line up of a charger against that warmachine, but 1) you are allowed to charge them 2)you can choose whether or notto not close the door as you desire as the attacker.
But I certainly understand the argument to the opposite.