What is the CR of this encounter....

[FCWesel]

...50 Medium Zombies.

 

[Alzrius]

Encounter Level...98.

1 Medium Zombie is CR 1/2, and every time you add another creature of the same CR, the EL is +2...so 49 more creatures that add +2 each is (49 x 2) + .5 = 98.5 rounded down becomes 98.

That said...that doesn't seem right at all, since a few fireballs and clerical turnings that result in the undead destroyed seem like they'd get rid of 50 zombies easily enough.

 

[Dash Dannigan]

Each time the number of creatures is doubled the EL goes up by 2. Yes, so you must double the number each time the EL increases:

# of Zombies = EL
1 = 1/2 CR
2 = 1 EL
4 = 3 EL
8 = 5 EL
16 = 7 EL
32 = 9 EL
64 = 11 EL

48 zombies would be EL 10. So that would be the EL for 50 zombies. Would need 14 more zombies to go up to EL of 11.

However the experience gained is for each zombie defeated at their CR. So that's 50 1/2 CR creatures. Say the party is 8th level they would receive 100 XP for each zombie (5,000 XP total to divide amongst party members). If the party is higher in level than 8th then no XP may be gained because the CR of the creatures is too low.

 

[Alzrius]

*points to what Dash said*

See, that makes a lot more sense.

 

[Grazzt]

Dash has it right. EL 10.