Way for GM to "fake" rolls?

Is there a way for a GM of a game (NOT a player) to "fake" the rolls of his RPG monsters?  For instance, in the instance when an encounter is too hard or too easy than it was supposed to be, having the enemies of the PCs suddenly fail their rolls or suddenly make more than usual would be a good way to even things out.  I'm looking for something that would say, roll a 1d10, but display the result as if the GM had rolled a 1d20, effectively eliminating the possibility of a roll over 10. Again, this would be for a GM only, not a normal player.  This was a good way to adjust on the fly when the GM rolls physical dice behind a GM screen, hoping there is a corollary on the Roll20 game.  Thanks!

Not really. The API (Pro subscription feature) can produce output like a roll and manipulate it however you please, but there will be a note at the bottom saying that it's API output. You could wrap your rolls in nested inline brackets to hide what the roll was (eg, instead of [[d20+5]] with the output "(10)+5=15", you'd use [[[[d20+5]]]] with the output "15"). You could also not show the rolls to your players, and simply report the result. You can achieve this by whispering the roll to yourself (/w JPicasso [[d20+5]] or /w gm [[d20+5]]), using the GM Roll command (/gr d20+5), or rolling the dice outside of Roll20 (up to and including using physical dice on your desk).

yes I use /gr unless I want them to see the roll.....

If you know that you want to "roll" a 15, you can just roll 15 (not d15, not d20, not d-anything). Example, /r 15 or [[15]]

Note that with any of the inline roll solutions ( [[15]], for example), your formula would still be visible to anyone who wanted to mouse over the result, so your players would know you fudged a roll, if they are canny enough to know about that. Your best bet, if you want to keep them guessing, is to just use whispered rolls to yourself.

Gozer the Gozerian said: Note that with any of the inline roll solutions ( [[15]], for example), your formula would still be visible to anyone who wanted to mouse over the result, You can get around this by wrapping all  your rolls in multiple levels of [[ ]] inline roll brackets. The mouse-over text only shows the outermost level of computation. For instance, if sending [[ 1d20 ]] results in 5, the mouseover will show "Rolling 1d20 = (5)". Sending [[ [[ 1d20 ]] ]] will show "Rolling 5 = 5". If you wrap all your rolls in multiple levels like this, players won't be able to distinguish between, for instance, [[ [[ 1d20 ]] ]] and [[ [[ 5 ]] ]]. EDIT: Ah, I see Brian already said this.

All I can say is: Don't do it. Don't fudge rolls. I can only speak for myself, but if I found out the GM was constantly cheating to get the outcome he wants, then I ask myself why are we even rolling dice?  And if you made an encounter to easy? Well, suck it up and move on. Let them have the day and feel like heroes.  If you messed up and made it to hard? That's a bit harder, but either tell them outright "damn I think I misjudged how hard these guys are, I'll nerf them a little". Have some NPC reinforcment arrive. Not a super NPC that owns everything, but a few low level guys that tie a few of the enemies up for one or two turns before they get slaughtered. Might give the PCs enough time to get the upper hand again. Just lower their stats a little, instead of a +10 roll a +7 instead. Most players won't notice. If they do, tell them the sentence from above. This is different from fudging rolls, where you essentially say "I want a 15".

David T. said: Gozer the Gozerian said: Note that with any of the inline roll solutions ( [[15]], for example), your formula would still be visible to anyone who wanted to mouse over the result, You can get around this by wrapping all  your rolls in multiple levels of [[ ]] inline roll brackets. The mouse-over text only shows the outermost level of computation. For instance, if sending [[ 1d20 ]] results in 5, the mouseover will show "Rolling 1d20 = (5)". Sending [[ [[ 1d20 ]] ]] will show "Rolling 5 = 5". If you wrap all your rolls in multiple levels like this, players won't be able to distinguish between, for instance, [[ [[ 1d20 ]] ]] and [[ [[ 5 ]] ]]. EDIT: Ah, I see Brian already said this. Yes sure you can do that... but it's not suspicious at all... /sarcasm

I know I am not adding too much in the "fudge the dice" solution but here is the method I use for hidden dice rolls. I output to my players that I am indeed rolling something behind the screen (with a dice roll SFX) so they get the IRL feeling of "The GM is rolling stuff behind the screen". Though I have yet to actually fudge a dice, it would be best to have a consensus with the players as to when you will be rolling everything to yourself or in the open. Then again if I were a player I would immediately question the GM as to why he wrapped his outcome in a million brackets.

Brother Sharp said: Then again if I were a player I would immediately question the GM as to why he wrapped his outcome in a million brackets. I do it simply to hide modifiers. 

I see it like Quatar. Don't fudge rolls. It might solve your problem right now, but it creates a new one one the long run. Keep in mind that, as a GM, you can always change the situation without cheating the rolls. Your encounter is too hard? Bring in a second group of adventurers that distract the NPCs during the battle (as Quatar already suggested).  The only healer of the team just triggered a deadly trap and is about to fall into a pit with spikes? Let the rest of the team do an extra roll if any of them just managed to grab the guy by his coat and save him from falling to death. Essentially, give one of the players a "hero moment"* Use some moral concept. Just having a huge encounter, and you noticed that, well, it is a bit too huge for the party? Let some of the NPCs panic when they see their best friend being grilled by a fireball, so they run away from the battle (either completely or just for a moment). Sometimes that already is enough to "turn the tide". Or have a "deus ex machina" NPC. I used to have an angel that, officially, appeared totally random (4 rolls a day, 1d20, angel appeared on a 20), with a lot of brimboriom. Flashes. Time freeze. You get the idea. And normally, he was just giving some hints about what the party should do next. But once or twice, made him appear right in a just-a-bit-too-hard situation. Time freezes, and he's like: "Oh, you look pretty beaten up. Let me heal you a bit." Technically the same thing as cheating a roll, but much more appreciated by the players. I removed him from the story later on, because I didn't want the players to rely on him. When they don't fear death any longer, they stop caring for their characters.  So, essentially: If you, as a GM, fake a roll, you are cheating yourself and your players. Because you can modify every situation to get what you want and, at the same time, make it more exciting for your friends. ___________________________________ * Hero moment: That's something that I try to have at least once per session anyway: One character gets a glorious moment. The barbarian that holds back a whole army of undead while his friends desperately try to unlock the exit. Or the wizard who screwed the evil lord good and proper by using prestidigitation. The rogue who stole the ancient magic artefact literally from a dragon's claws. But even there, I don't fudge the rolls. Either I just don't roll at all, or I modify the situation so the PC can roll again without facing any bad consequences. The barbarian holding of the undead? For some reason they don't attack him directly, but just want to crawl over him to reach the other guys. The evil lord: Knows that you used some magic cheat, but still, that ring looks EXACTLY like the one he gave his daughter so many years ago. And so on...

I would go with Brother Sharp 's idea.  Set up a marco that lets the player know (or thnk) that you are rolling dice, and send the results in a whisper straight to the GM (you).  Or just make up a number.  No hassle, and get the players paranoind.