ExploderWizard
Hero
Well let's put some nuance in the situation. Let's assume that this is not a game where the PCs have normally have access to the monster stat blocks or current monster hit points. Which kinds of scenarios would you, or the other posters in the thread find acceptable?
I guess the point of the above examples is that as a DM, you are responsible for designing the scenario, and sometimes you make mistakes. You typically only have one chance to correct the mistakes, and that is right at the table, as you play.
- You, as the DM, have decided that the necromantic power in the room gives the skeletons within the ability to regenerate 15 hit points a round. After a few rounds, it becomes apparent that if the PCs can win at all, it will take hours to resolve. Without announcing the change, you reduce the amount of regeneration to 3 hit points.
- Same as above, but you announce it, attributing it to one of the PCs actions. "As you bring a holy symbol near the evil altar, the necromantic energy in the room dims!"
- You want your villain to be powerful and menacing, so you give his main attack the ability to crit on a roll of 16-20 for 6d8 extra damage. His first crit, on a natural 20, kills a PC. You decide to immediately remove the extra critical range.
- Same as above, but instead of being your own creation, the villain came from Dragon magazine or the Monster Manual.
- Same as #3, but you did not immediately decide whether to remove the extra critical range. You've just rolled a 17 against a PC you know has 5 hit points left. You announce a normal (non-critical) hit and roll normal damage.
- You are running a one-shot adventure with your normal group, but at a much higher level than you normally play. Your players have been bragging about how optimized their characters are all week. You decide to add 2 extra monsters to each planned encounter. As the first combat breaks out, it becomes apparent that the players barely know what their characters abilities do, and are actually less effective than normal. You remove the extra monsters from future combats.
- Same as above, but you remove the extra monsters from the present combat by sneaking the figures off the table when no one is looking.
- Same as above, but instead, you announce that the extra monsters are joining another, nearby battle with some NPCs that the players are not expected to participate in.
1) Nope. If powerful regeneration was important to the area I wouldn't discard it. It would be very obvious to anyone there what was happening. There would certainly be alternative ways of dealing with the situation other than chopping through a roomful of augmented skellies.
2) As per #1
3) Could only happen if handed material to run verbatim on a playtest.
4) See #3
5) See #3
6) If I added the extra monsters then I would have added additional rewards as well. I would let the extra monsters stand in that situation. The players can learn on the fly or suffer a TPK.
7)



8) I would rather have a reputation as a killer DM instead of setting up my game for major league action then playing teeball once the PC's are at bat.